draft-ietf-calsify-rfc2445bis-10.txt   rfc5545.txt 
Network Working Group B. Desruisseaux, Ed. Network Working Group B. Desruisseaux, Ed.
Internet-Draft Oracle Request for Comments: 5545 Oracle
Obsoletes: 2445 (if approved) April 20, 2009 Obsoletes: 2445 September 2009
Intended status: Standards Track Category: Standards Track
Expires: October 22, 2009
Internet Calendaring and Scheduling Core Object Specification Internet Calendaring and Scheduling Core Object Specification
(iCalendar) (iCalendar)
draft-ietf-calsify-rfc2445bis-10
Abstract
This document defines the iCalendar data format for representing and
exchanging calendaring and scheduling information such as events,
to-dos, journal entries, and free/busy information, independent of any
particular calendar service or protocol.
Status of This Memo Status of This Memo
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This Internet-Draft will expire on October 22, 2009. RFC 5545 iCalendar September 2009
Copyright Notice it for publication as an RFC or to translate it into languages other
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Copyright (c) 2009 IETF Trust and the persons identified as the Table of Contents
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 5
Provisions Relating to IETF Documents in effect on the date of 2. Basic Grammar and Conventions . . . . . . . . . . . . . . . . 6
publication of this document (http://trustee.ietf.org/license-info). 2.1. Formatting Conventions . . . . . . . . . . . . . . . . . 6
Please review these documents carefully, as they describe your rights 2.2. Related Memos . . . . . . . . . . . . . . . . . . . . . . 7
and restrictions with respect to this document. 3. iCalendar Object Specification . . . . . . . . . . . . . . . 8
3.1. Content Lines . . . . . . . . . . . . . . . . . . . . . . 8
3.1.1. List and Field Separators . . . . . . . . . . . . . . 11
3.1.2. Multiple Values . . . . . . . . . . . . . . . . . . . 11
3.1.3. Binary Content . . . . . . . . . . . . . . . . . . . 11
3.1.4. Character Set . . . . . . . . . . . . . . . . . . . . 12
3.2. Property Parameters . . . . . . . . . . . . . . . . . . . 12
3.2.1. Alternate Text Representation . . . . . . . . . . . . 13
3.2.2. Common Name . . . . . . . . . . . . . . . . . . . . . 15
3.2.3. Calendar User Type . . . . . . . . . . . . . . . . . 15
3.2.4. Delegators . . . . . . . . . . . . . . . . . . . . . 16
3.2.5. Delegatees . . . . . . . . . . . . . . . . . . . . . 16
3.2.6. Directory Entry Reference . . . . . . . . . . . . . . 17
3.2.7. Inline Encoding . . . . . . . . . . . . . . . . . . . 17
3.2.8. Format Type . . . . . . . . . . . . . . . . . . . . . 18
3.2.9. Free/Busy Time Type . . . . . . . . . . . . . . . . . 19
3.2.10. Language . . . . . . . . . . . . . . . . . . . . . . 20
3.2.11. Group or List Membership . . . . . . . . . . . . . . 20
3.2.12. Participation Status . . . . . . . . . . . . . . . . 21
3.2.13. Recurrence Identifier Range . . . . . . . . . . . . . 22
3.2.14. Alarm Trigger Relationship . . . . . . . . . . . . . 23
3.2.15. Relationship Type . . . . . . . . . . . . . . . . . . 24
3.2.16. Participation Role . . . . . . . . . . . . . . . . . 25
3.2.17. RSVP Expectation . . . . . . . . . . . . . . . . . . 25
3.2.18. Sent By . . . . . . . . . . . . . . . . . . . . . . . 26
3.2.19. Time Zone Identifier . . . . . . . . . . . . . . . . 26
3.2.20. Value Data Types . . . . . . . . . . . . . . . . . . 28
3.3. Property Value Data Types . . . . . . . . . . . . . . . . 29
3.3.1. Binary . . . . . . . . . . . . . . . . . . . . . . . 29
3.3.2. Boolean . . . . . . . . . . . . . . . . . . . . . . . 30
3.3.3. Calendar User Address . . . . . . . . . . . . . . . . 30
3.3.4. Date . . . . . . . . . . . . . . . . . . . . . . . . 31
3.3.5. Date-Time . . . . . . . . . . . . . . . . . . . . . . 31
3.3.6. Duration . . . . . . . . . . . . . . . . . . . . . . 34
3.3.7. Float . . . . . . . . . . . . . . . . . . . . . . . . 35
3.3.8. Integer . . . . . . . . . . . . . . . . . . . . . . . 35
3.3.9. Period of Time . . . . . . . . . . . . . . . . . . . 36
3.3.10. Recurrence Rule . . . . . . . . . . . . . . . . . . . 37
3.3.11. Text . . . . . . . . . . . . . . . . . . . . . . . . 45
Abstract RFC 5545 iCalendar September 2009
This document defines the iCalendar data format for representing and 3.3.12. Time . . . . . . . . . . . . . . . . . . . . . . . . 46
exchanging calendaring and scheduling information such as events, to- 3.3.13. URI . . . . . . . . . . . . . . . . . . . . . . . . . 48
dos, journal entries and free/busy information, independent of any 3.3.14. UTC Offset . . . . . . . . . . . . . . . . . . . . . 49
particular calendar service or protocol. 3.4. iCalendar Object . . . . . . . . . . . . . . . . . . . . 49
3.5. Property . . . . . . . . . . . . . . . . . . . . . . . . 50
3.6. Calendar Components . . . . . . . . . . . . . . . . . . . 50
3.6.1. Event Component . . . . . . . . . . . . . . . . . . . 52
3.6.2. To-Do Component . . . . . . . . . . . . . . . . . . . 56
3.6.3. Journal Component . . . . . . . . . . . . . . . . . . 58
3.6.4. Free/Busy Component . . . . . . . . . . . . . . . . . 60
3.6.5. Time Zone Component . . . . . . . . . . . . . . . . . 63
3.6.6. Alarm Component . . . . . . . . . . . . . . . . . . . 72
3.7. Calendar Properties . . . . . . . . . . . . . . . . . . . 77
3.7.1. Calendar Scale . . . . . . . . . . . . . . . . . . . 77
3.7.2. Method . . . . . . . . . . . . . . . . . . . . . . . 78
3.7.3. Product Identifier . . . . . . . . . . . . . . . . . 79
3.7.4. Version . . . . . . . . . . . . . . . . . . . . . . . 80
3.8. Component Properties . . . . . . . . . . . . . . . . . . 81
3.8.1. Descriptive Component Properties . . . . . . . . . . 81
3.8.1.1. Attachment . . . . . . . . . . . . . . . . . . . 81
3.8.1.2. Categories . . . . . . . . . . . . . . . . . . . 82
3.8.1.3. Classification . . . . . . . . . . . . . . . . . 83
3.8.1.4. Comment . . . . . . . . . . . . . . . . . . . . . 84
3.8.1.5. Description . . . . . . . . . . . . . . . . . . . 85
3.8.1.6. Geographic Position . . . . . . . . . . . . . . . 87
3.8.1.7. Location . . . . . . . . . . . . . . . . . . . . 88
3.8.1.8. Percent Complete . . . . . . . . . . . . . . . . 89
3.8.1.9. Priority . . . . . . . . . . . . . . . . . . . . 90
3.8.1.10. Resources . . . . . . . . . . . . . . . . . . . . 92
3.8.1.11. Status . . . . . . . . . . . . . . . . . . . . . 93
3.8.1.12. Summary . . . . . . . . . . . . . . . . . . . . . 94
3.8.2. Date and Time Component Properties . . . . . . . . . 95
3.8.2.1. Date-Time Completed . . . . . . . . . . . . . . . 95
3.8.2.2. Date-Time End . . . . . . . . . . . . . . . . . . 96
3.8.2.3. Date-Time Due . . . . . . . . . . . . . . . . . . 97
3.8.2.4. Date-Time Start . . . . . . . . . . . . . . . . . 99
3.8.2.5. Duration . . . . . . . . . . . . . . . . . . . . 100
3.8.2.6. Free/Busy Time . . . . . . . . . . . . . . . . . 101
3.8.2.7. Time Transparency . . . . . . . . . . . . . . . . 102
3.8.3. Time Zone Component Properties . . . . . . . . . . . 103
3.8.3.1. Time Zone Identifier . . . . . . . . . . . . . . 103
3.8.3.2. Time Zone Name . . . . . . . . . . . . . . . . . 105
3.8.3.3. Time Zone Offset From . . . . . . . . . . . . . . 106
3.8.3.4. Time Zone Offset To . . . . . . . . . . . . . . . 106
3.8.3.5. Time Zone URL . . . . . . . . . . . . . . . . . . 107
3.8.4. Relationship Component Properties . . . . . . . . . . 108
3.8.4.1. Attendee . . . . . . . . . . . . . . . . . . . . 108
3.8.4.2. Contact . . . . . . . . . . . . . . . . . . . . . 111
Editorial Note (To be removed by RFC Editor prior to publication) RFC 5545 iCalendar September 2009
This document is a product of the Calendaring and Scheduling 3.8.4.3. Organizer . . . . . . . . . . . . . . . . . . . . 113
Standards Simplification (Calsify) working group of the Internet 3.8.4.4. Recurrence ID . . . . . . . . . . . . . . . . . . 114
Engineering Task Force. Comments on this draft are welcomed, and 3.8.4.5. Related To . . . . . . . . . . . . . . . . . . . 117
should be addressed to the ietf-calsify@osafoundation.org [1] mailing 3.8.4.6. Uniform Resource Locator . . . . . . . . . . . . 118
list. 3.8.4.7. Unique Identifier . . . . . . . . . . . . . . . . 119
3.8.5. Recurrence Component Properties . . . . . . . . . . . 120
3.8.5.1. Exception Date-Times . . . . . . . . . . . . . . 120
3.8.5.2. Recurrence Date-Times . . . . . . . . . . . . . . 122
3.8.5.3. Recurrence Rule . . . . . . . . . . . . . . . . . 124
3.8.6. Alarm Component Properties . . . . . . . . . . . . . 134
3.8.6.1. Action . . . . . . . . . . . . . . . . . . . . . 134
3.8.6.2. Repeat Count . . . . . . . . . . . . . . . . . . 135
3.8.6.3. Trigger . . . . . . . . . . . . . . . . . . . . . 135
3.8.7. Change Management Component Properties . . . . . . . 138
3.8.7.1. Date-Time Created . . . . . . . . . . . . . . . . 138
3.8.7.2. Date-Time Stamp . . . . . . . . . . . . . . . . . 139
3.8.7.3. Last Modified . . . . . . . . . . . . . . . . . . 140
3.8.7.4. Sequence Number . . . . . . . . . . . . . . . . . 141
3.8.8. Miscellaneous Component Properties . . . . . . . . . 142
3.8.8.1. IANA Properties . . . . . . . . . . . . . . . . . 142
3.8.8.2. Non-Standard Properties . . . . . . . . . . . . . 142
3.8.8.3. Request Status . . . . . . . . . . . . . . . . . 144
4. iCalendar Object Examples . . . . . . . . . . . . . . . . . . 146
5. Recommended Practices . . . . . . . . . . . . . . . . . . . . 150
6. Internationalization Considerations . . . . . . . . . . . . . 151
7. Security Considerations . . . . . . . . . . . . . . . . . . . 151
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 151
8.1. iCalendar Media Type Registration . . . . . . . . . . . . 151
8.2. New iCalendar Elements Registration . . . . . . . . . . . 155
8.2.1. iCalendar Elements Registration Procedure . . . . . . 155
8.2.2. Registration Template for Components . . . . . . . . 155
8.2.3. Registration Template for Properties . . . . . . . . 156
8.2.4. Registration Template for Parameters . . . . . . . . 156
8.2.5. Registration Template for Value Data Types . . . . . 157
8.2.6. Registration Template for Values . . . . . . . . . . 157
8.3. Initial iCalendar Elements Registries . . . . . . . . . . 158
8.3.1. Components Registry . . . . . . . . . . . . . . . . . 158
8.3.2. Properties Registry . . . . . . . . . . . . . . . . . 158
8.3.3. Parameters Registry . . . . . . . . . . . . . . . . . 161
8.3.4. Value Data Types Registry . . . . . . . . . . . . . . 162
8.3.5. Calendar User Types Registry . . . . . . . . . . . . 162
8.3.6. Free/Busy Time Types Registry . . . . . . . . . . . . 163
8.3.7. Participation Statuses Registry . . . . . . . . . . . 163
8.3.8. Relationship Types Registry . . . . . . . . . . . . . 164
8.3.9. Participation Roles Registry . . . . . . . . . . . . 164
8.3.10. Actions Registry . . . . . . . . . . . . . . . . . . 165
8.3.11. Classifications Registry . . . . . . . . . . . . . . 165
8.3.12. Methods Registry . . . . . . . . . . . . . . . . . . 165
Table of Contents RFC 5545 iCalendar September 2009
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 8 9. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 165
2. Basic Grammar and Conventions . . . . . . . . . . . . . . . . 9 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 166
2.1. Formatting Conventions . . . . . . . . . . . . . . . . . 9 10.1. Normative References . . . . . . . . . . . . . . . . . . 166
2.2. Related Memos . . . . . . . . . . . . . . . . . . . . . . 10 10.2. Informative References . . . . . . . . . . . . . . . . . 167
3. iCalendar Object Specification . . . . . . . . . . . . . . . 11 Appendix A. Differences from RFC 2445 . . . . . . . . . . . . . 169
3.1. Content Lines . . . . . . . . . . . . . . . . . . . . . . 11 A.1. New Restrictions . . . . . . . . . . . . . . . . . . . . 169
3.1.1. List and Field Separators . . . . . . . . . . . . . . 13 A.2. Restrictions Removed . . . . . . . . . . . . . . . . . . 169
3.1.2. Multiple Values . . . . . . . . . . . . . . . . . . . 14 A.3. Deprecated Features . . . . . . . . . . . . . . . . . . . 169
3.1.3. Binary Content . . . . . . . . . . . . . . . . . . . 14
3.1.4. Character Set . . . . . . . . . . . . . . . . . . . . 15
3.2. Property Parameters . . . . . . . . . . . . . . . . . . . 15
3.2.1. Alternate Text Representation . . . . . . . . . . . . 16
3.2.2. Common Name . . . . . . . . . . . . . . . . . . . . . 17
3.2.3. Calendar User Type . . . . . . . . . . . . . . . . . 18
3.2.4. Delegators . . . . . . . . . . . . . . . . . . . . . 19
3.2.5. Delegatees . . . . . . . . . . . . . . . . . . . . . 19
3.2.6. Directory Entry Reference . . . . . . . . . . . . . . 20
3.2.7. Inline Encoding . . . . . . . . . . . . . . . . . . . 20
3.2.8. Format Type . . . . . . . . . . . . . . . . . . . . . 21
3.2.9. Free/Busy Time Type . . . . . . . . . . . . . . . . . 22
3.2.10. Language . . . . . . . . . . . . . . . . . . . . . . 23
3.2.11. Group or List Membership . . . . . . . . . . . . . . 23
3.2.12. Participation Status . . . . . . . . . . . . . . . . 24
3.2.13. Recurrence Identifier Range . . . . . . . . . . . . . 25
3.2.14. Alarm Trigger Relationship . . . . . . . . . . . . . 26
3.2.15. Relationship Type . . . . . . . . . . . . . . . . . . 27
3.2.16. Participation Role . . . . . . . . . . . . . . . . . 28
3.2.17. RSVP Expectation . . . . . . . . . . . . . . . . . . 28
3.2.18. Sent By . . . . . . . . . . . . . . . . . . . . . . . 29
3.2.19. Time Zone Identifier . . . . . . . . . . . . . . . . 29
3.2.20. Value Data Types . . . . . . . . . . . . . . . . . . 31
3.3. Property Value Data Types . . . . . . . . . . . . . . . . 32
3.3.1. Binary . . . . . . . . . . . . . . . . . . . . . . . 32
3.3.2. Boolean . . . . . . . . . . . . . . . . . . . . . . . 33
3.3.3. Calendar User Address . . . . . . . . . . . . . . . . 33
3.3.4. Date . . . . . . . . . . . . . . . . . . . . . . . . 34
3.3.5. Date-Time . . . . . . . . . . . . . . . . . . . . . . 34
3.3.6. Duration . . . . . . . . . . . . . . . . . . . . . . 37
3.3.7. Float . . . . . . . . . . . . . . . . . . . . . . . . 38
3.3.8. Integer . . . . . . . . . . . . . . . . . . . . . . . 39
3.3.9. Period of Time . . . . . . . . . . . . . . . . . . . 39
3.3.10. Recurrence Rule . . . . . . . . . . . . . . . . . . . 40
3.3.11. Text . . . . . . . . . . . . . . . . . . . . . . . . 48
3.3.12. Time . . . . . . . . . . . . . . . . . . . . . . . . 49
3.3.13. URI . . . . . . . . . . . . . . . . . . . . . . . . . 51
3.3.14. UTC Offset . . . . . . . . . . . . . . . . . . . . . 52
3.4. iCalendar Object . . . . . . . . . . . . . . . . . . . . 53
3.5. Property . . . . . . . . . . . . . . . . . . . . . . . . 54
3.6. Calendar Components . . . . . . . . . . . . . . . . . . . 54
3.6.1. Event Component . . . . . . . . . . . . . . . . . . . 56
3.6.2. To-do Component . . . . . . . . . . . . . . . . . . . 60
3.6.3. Journal Component . . . . . . . . . . . . . . . . . . 62
3.6.4. Free/Busy Component . . . . . . . . . . . . . . . . . 64
3.6.5. Time Zone Component . . . . . . . . . . . . . . . . . 67
3.6.6. Alarm Component . . . . . . . . . . . . . . . . . . . 76
3.7. Calendar Properties . . . . . . . . . . . . . . . . . . . 81
3.7.1. Calendar Scale . . . . . . . . . . . . . . . . . . . 81
3.7.2. Method . . . . . . . . . . . . . . . . . . . . . . . 82
3.7.3. Product Identifier . . . . . . . . . . . . . . . . . 83
3.7.4. Version . . . . . . . . . . . . . . . . . . . . . . . 84
3.8. Component Properties . . . . . . . . . . . . . . . . . . 85
3.8.1. Descriptive Component Properties . . . . . . . . . . 85
3.8.1.1. Attachment . . . . . . . . . . . . . . . . . . . 85
3.8.1.2. Categories . . . . . . . . . . . . . . . . . . . 86
3.8.1.3. Classification . . . . . . . . . . . . . . . . . 87
3.8.1.4. Comment . . . . . . . . . . . . . . . . . . . . . 88
3.8.1.5. Description . . . . . . . . . . . . . . . . . . . 89
3.8.1.6. Geographic Position . . . . . . . . . . . . . . . 91
3.8.1.7. Location . . . . . . . . . . . . . . . . . . . . 92
3.8.1.8. Percent Complete . . . . . . . . . . . . . . . . 93
3.8.1.9. Priority . . . . . . . . . . . . . . . . . . . . 94
3.8.1.10. Resources . . . . . . . . . . . . . . . . . . . . 96
3.8.1.11. Status . . . . . . . . . . . . . . . . . . . . . 97
3.8.1.12. Summary . . . . . . . . . . . . . . . . . . . . . 98
3.8.2. Date and Time Component Properties . . . . . . . . . 100
3.8.2.1. Date/Time Completed . . . . . . . . . . . . . . . 100
3.8.2.2. Date/Time End . . . . . . . . . . . . . . . . . . 100
3.8.2.3. Date/Time Due . . . . . . . . . . . . . . . . . . 102
3.8.2.4. Date/Time Start . . . . . . . . . . . . . . . . . 103
3.8.2.5. Duration . . . . . . . . . . . . . . . . . . . . 104
3.8.2.6. Free/Busy Time . . . . . . . . . . . . . . . . . 105
3.8.2.7. Time Transparency . . . . . . . . . . . . . . . . 106
3.8.3. Time Zone Component Properties . . . . . . . . . . . 107
3.8.3.1. Time Zone Identifier . . . . . . . . . . . . . . 107
3.8.3.2. Time Zone Name . . . . . . . . . . . . . . . . . 109
3.8.3.3. Time Zone Offset From . . . . . . . . . . . . . . 110
3.8.3.4. Time Zone Offset To . . . . . . . . . . . . . . . 110
3.8.3.5. Time Zone URL . . . . . . . . . . . . . . . . . . 111
3.8.4. Relationship Component Properties . . . . . . . . . . 112
3.8.4.1. Attendee . . . . . . . . . . . . . . . . . . . . 112
3.8.4.2. Contact . . . . . . . . . . . . . . . . . . . . . 115
3.8.4.3. Organizer . . . . . . . . . . . . . . . . . . . . 117
3.8.4.4. Recurrence ID . . . . . . . . . . . . . . . . . . 118
3.8.4.5. Related To . . . . . . . . . . . . . . . . . . . 121
3.8.4.6. Uniform Resource Locator . . . . . . . . . . . . 122
3.8.4.7. Unique Identifier . . . . . . . . . . . . . . . . 123
3.8.5. Recurrence Component Properties . . . . . . . . . . . 124
3.8.5.1. Exception Date/Times . . . . . . . . . . . . . . 124
3.8.5.2. Recurrence Date/Times . . . . . . . . . . . . . . 126
3.8.5.3. Recurrence Rule . . . . . . . . . . . . . . . . . 128
3.8.6. Alarm Component Properties . . . . . . . . . . . . . 138
3.8.6.1. Action . . . . . . . . . . . . . . . . . . . . . 138
3.8.6.2. Repeat Count . . . . . . . . . . . . . . . . . . 139
3.8.6.3. Trigger . . . . . . . . . . . . . . . . . . . . . 139
3.8.7. Change Management Component Properties . . . . . . . 142
3.8.7.1. Date/Time Created . . . . . . . . . . . . . . . . 142
3.8.7.2. Date/Time Stamp . . . . . . . . . . . . . . . . . 143
3.8.7.3. Last Modified . . . . . . . . . . . . . . . . . . 144
3.8.7.4. Sequence Number . . . . . . . . . . . . . . . . . 145
3.8.8. Miscellaneous Component Properties . . . . . . . . . 146
3.8.8.1. IANA Properties . . . . . . . . . . . . . . . . . 146
3.8.8.2. Non-standard Properties . . . . . . . . . . . . . 146
3.8.8.3. Request Status . . . . . . . . . . . . . . . . . 148
4. iCalendar Object Examples . . . . . . . . . . . . . . . . . . 151
5. Recommended Practices . . . . . . . . . . . . . . . . . . . . 156
6. Internationalization Considerations . . . . . . . . . . . . . 157
7. Security Considerations . . . . . . . . . . . . . . . . . . . 158
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 159
8.1. iCalendar Media Type Registration . . . . . . . . . . . . 159
8.2. New iCalendar Elements Registration . . . . . . . . . . . 162
8.2.1. iCalendar Elements Registration Procedure . . . . . . 162
8.2.2. Registration Template for Components . . . . . . . . 162
8.2.3. Registration Template for Properties . . . . . . . . 163
8.2.4. Registration Template for Parameters . . . . . . . . 164
8.2.5. Registration Template for Value Data Types . . . . . 164
8.2.6. Registration Template for Values . . . . . . . . . . 164
8.3. Initial iCalendar Elements Registries . . . . . . . . . . 165
8.3.1. Components Registry . . . . . . . . . . . . . . . . . 165
8.3.2. Properties Registry . . . . . . . . . . . . . . . . . 166
8.3.3. Parameters Registry . . . . . . . . . . . . . . . . . 168
8.3.4. Value Data Types Registry . . . . . . . . . . . . . . 170
8.3.5. Calendar User Types Registry . . . . . . . . . . . . 170
8.3.6. Free/Busy Time Types Registry . . . . . . . . . . . . 171
8.3.7. Participation Statuses Registry . . . . . . . . . . . 171
8.3.8. Relationship Types Registry . . . . . . . . . . . . . 172
8.3.9. Participation Roles Registry . . . . . . . . . . . . 172
8.3.10. Actions Registry . . . . . . . . . . . . . . . . . . 173
8.3.11. Classifications Registry . . . . . . . . . . . . . . 173
8.3.12. Methods Registry . . . . . . . . . . . . . . . . . . 173
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 174
10. References . . . . . . . . . . . . . . . . . . . . . . . . . 175
10.1. Normative References . . . . . . . . . . . . . . . . . . 175
10.2. Informative References . . . . . . . . . . . . . . . . . 176
Appendix A. Differences from RFC 2445 . . . . . . . . . . . . . 179
A.1. New restrictions . . . . . . . . . . . . . . . . . . . . 179
A.2. Restrictions removed . . . . . . . . . . . . . . . . . . 179
A.3. Deprecated features . . . . . . . . . . . . . . . . . . . 179
Appendix B. Change Log (to be removed by RFC Editor prior to
publication) . . . . . . . . . . . . . . . . . . . . 180
B.1. Changes in -10 . . . . . . . . . . . . . . . . . . . . . 180
B.2. Changes in -09 . . . . . . . . . . . . . . . . . . . . . 180
B.3. Changes in -08 . . . . . . . . . . . . . . . . . . . . . 181
B.4. Changes in -07 . . . . . . . . . . . . . . . . . . . . . 182
B.5. Changes in -06 . . . . . . . . . . . . . . . . . . . . . 183
B.6. Changes in -05 . . . . . . . . . . . . . . . . . . . . . 185
B.7. Changes in -04 . . . . . . . . . . . . . . . . . . . . . 185
B.8. Changes in -03 . . . . . . . . . . . . . . . . . . . . . 187
B.9. Changes in -02 . . . . . . . . . . . . . . . . . . . . . 187
B.10. Changes in -01 . . . . . . . . . . . . . . . . . . . . . 188
1. Introduction 1. Introduction
The use of calendaring and scheduling has grown considerably in the The use of calendaring and scheduling has grown considerably in the
last decade. Enterprise and inter-enterprise business has become last decade. Enterprise and inter-enterprise business has become
dependent on rapid scheduling of events and actions using this dependent on rapid scheduling of events and actions using this
information technology. This memo is intended to progress the level information technology. This memo is intended to progress the level
of interoperability possible between dissimilar calendaring and of interoperability possible between dissimilar calendaring and
scheduling applications. This memo defines a MIME content type for scheduling applications. This memo defines a MIME content type for
exchanging electronic calendaring and scheduling information. The exchanging electronic calendaring and scheduling information. The
Internet Calendaring and Scheduling Core Object Specification, or Internet Calendaring and Scheduling Core Object Specification, or
iCalendar, allows for the capture and exchange of information iCalendar, allows for the capture and exchange of information
normally stored within a calendaring and scheduling application; such normally stored within a calendaring and scheduling application; such
as a Personal Information Manager (PIM) or a Group Scheduling as a Personal Information Manager (PIM) or a Group-Scheduling
product. product.
The iCalendar format is suitable as an exchange format between The iCalendar format is suitable as an exchange format between
applications or systems. The format is defined in terms of a MIME applications or systems. The format is defined in terms of a MIME
content type. This will enable the object to be exchanged using content type. This will enable the object to be exchanged using
several transports, including but not limited to SMTP, HTTP, a file several transports, including but not limited to SMTP, HTTP, a file
system, desktop interactive protocols such as the use of a memory- system, desktop interactive protocols such as the use of a memory-
based clipboard or drag/drop interactions, point-to-point based clipboard or drag/drop interactions, point-to-point
asynchronous communication, wired-network transport, or some form of asynchronous communication, wired-network transport, or some form of
unwired transport such as infrared might also be used. unwired transport such as infrared.
The memo also provides for the definition of iCalendar object methods The memo also provides for the definition of iCalendar object methods
that will map this content type to a set of messages for supporting that will map this content type to a set of messages for supporting
calendaring and scheduling operations such as requesting, replying calendaring and scheduling operations such as requesting, replying
to, modifying, and canceling meetings or appointments, to-dos and to, modifying, and canceling meetings or appointments, to-dos, and
journal entries. The iCalendar object methods can be used to define journal entries. The iCalendar object methods can be used to define
other calendaring and scheduling operations such a requesting for and other calendaring and scheduling operations such as requesting for
replying with free/busy time data. Such a scheduling protocol is and replying with free/busy time data. Such a scheduling protocol is
defined in the iCalendar Transport-independent Interoperability defined in the iCalendar Transport-independent Interoperability
Protocol (iTIP) defined in [I-D.ietf-calsify-2446bis]. Protocol (iTIP) defined in [2446bis].
The memo also includes a formal grammar for the content type based on The memo also includes a formal grammar for the content type based on
the Internet ABNF defined in [RFC5234]. This ABNF is required for the Internet ABNF defined in [RFC5234]. This ABNF is required for
the implementation of parsers and to serve as the definitive the implementation of parsers and to serve as the definitive
reference when ambiguities or questions arise in interpreting the reference when ambiguities or questions arise in interpreting the
descriptive prose definition of the memo. Additional restrictions descriptive prose definition of the memo. Additional restrictions
RFC 5545 iCalendar September 2009
that could not easily be expressed with the ABNF syntax are specified that could not easily be expressed with the ABNF syntax are specified
as comments in the ABNF. Comments with normative statements should as comments in the ABNF. Comments with normative statements should
be treated as such. be treated as such.
2. Basic Grammar and Conventions 2. Basic Grammar and Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
skipping to change at page 9, line 22 skipping to change at page 6, line 28
notation for defining the calendaring and scheduling format. notation for defining the calendaring and scheduling format.
The notation used in this memo is the ABNF notation of [RFC5234]. The notation used in this memo is the ABNF notation of [RFC5234].
Readers intending on implementing the format defined in this memo Readers intending on implementing the format defined in this memo
should be familiar with this notation in order to properly interpret should be familiar with this notation in order to properly interpret
the specifications of this memo. the specifications of this memo.
All numeric values used in this memo are given in decimal notation. All numeric values used in this memo are given in decimal notation.
All names of properties, property parameters, enumerated property All names of properties, property parameters, enumerated property
values and property parameter values are case-insensitive. However, values, and property parameter values are case-insensitive. However,
all other property values are case-sensitive, unless otherwise all other property values are case-sensitive, unless otherwise
stated. stated.
Note: All indented editorial notes, such as this one, are intended Note: All indented editorial notes, such as this one, are intended
to provide the reader with additional information. The to provide the reader with additional information. The
information is not essential to the building of an implementation information is not essential to the building of an implementation
conformant with this memo. The information is provided to conformant with this memo. The information is provided to
highlight a particular feature or characteristic of the memo. highlight a particular feature or characteristic of the memo.
The format for the iCalendar object is based on the syntax of the The format for the iCalendar object is based on the syntax of the
text/directory media type [RFC2425]. While the iCalendar object is text/directory media type [RFC2425]. While the iCalendar object is
not a profile of the text/directory media type [RFC2425], it does not a profile of the text/directory media type [RFC2425], it does
reuse a number of the elements from the [RFC2425] specification. reuse a number of the elements from the [RFC2425] specification.
2.1. Formatting Conventions 2.1. Formatting Conventions
The elements defined in this memo are defined in prose. Many of the The elements defined in this memo are defined in prose. Many of the
terms used to describe these have common usage that is different than terms used to describe these have common usage that is different than
the standards usage of this memo. In order to reference within this the standards usage of this memo. In order to reference, within this
memo elements of the calendaring and scheduling model, core object memo, elements of the calendaring and scheduling model, core object
(this memo) or interoperability protocol [I-D.ietf-calsify-2446bis] (this memo), or interoperability protocol [2446bis] some formatting
some formatting conventions have been used. Calendaring and conventions have been used. Calendaring and scheduling roles are
scheduling roles are referred to in quoted-strings of text with the referred to in quoted-strings of text with the first character of
first character of each word in upper case. For example, "Organizer" each word in uppercase. For example, "Organizer" refers to a role of
refers to a role of a "Calendar User" within the scheduling protocol a "Calendar User" within the scheduling protocol defined by
defined by [I-D.ietf-calsify-2446bis]. Calendar components defined [2446bis]. Calendar components defined by this memo are referred to
by this memo are referred to with capitalized, quoted-strings of
text. All calendar components start with the letter "V". For RFC 5545 iCalendar September 2009
example, "VEVENT" refers to the event calendar component, "VTODO"
refers to the to-do calendar component and "VJOURNAL" refers to the with capitalized, quoted-strings of text. All calendar components
daily journal calendar component. Scheduling methods defined by iTIP start with the letter "V". For example, "VEVENT" refers to the event
[I-D.ietf-calsify-2446bis] are referred to with capitalized, quoted- calendar component, "VTODO" refers to the to-do calendar component,
strings of text. For example, "REQUEST" refers to the method for and "VJOURNAL" refers to the daily journal calendar component.
requesting a scheduling calendar component be created or modified, Scheduling methods defined by iTIP [2446bis] are referred to with
"REPLY" refers to the method a recipient of a request uses to update capitalized, quoted-strings of text. For example, "REQUEST" refers
their status with the "Organizer" of the calendar component. to the method for requesting a scheduling calendar component be
created or modified, and "REPLY" refers to the method a recipient of
a request uses to update their status with the "Organizer" of the
calendar component.
The properties defined by this memo are referred to with capitalized, The properties defined by this memo are referred to with capitalized,
quoted-strings of text, followed by the word "property". For quoted-strings of text, followed by the word "property". For
example, "ATTENDEE" property refers to the iCalendar property used to example, "ATTENDEE" property refers to the iCalendar property used to
convey the calendar address of a calendar user. Property parameters convey the calendar address of a calendar user. Property parameters
defined by this memo are referred to with lowercase, quoted-strings defined by this memo are referred to with lowercase, quoted-strings
of text, followed by the word "parameter". For example, "value" of text, followed by the word "parameter". For example, "value"
parameter refers to the iCalendar property parameter used to override parameter refers to the iCalendar property parameter used to override
the default value type for a property value. Enumerated values the default value type for a property value. Enumerated values
defined by this memo are referred to with capitalized text, either defined by this memo are referred to with capitalized text, either
alone or followed by the word "value". For example, the "MINUTELY" alone or followed by the word "value". For example, the "MINUTELY"
value can be used with the "FREQ" component of the "RECUR" value type value can be used with the "FREQ" component of the "RECUR" value type
to specify repeating components based on an interval of one minute or to specify repeating components based on an interval of one minute or
more. more.
In this document, descriptions of characters are of the form The following table lists the different characters from the
"character name (codepoint)", where "codepoint" is from the US-ASCII [US-ASCII] character set that is referenced in this document. For
character set. The "character name" is the authoritative each character, the table specifies the character name used
description; (codepoint) is a reference to that character in US- throughout this document, along with its US-ASCII decimal codepoint.
ASCII.
RFC 5545 iCalendar September 2009
+------------------------+-------------------+
| Character name | Decimal codepoint |
+------------------------+-------------------+
| HTAB | 9 |
| LF | 10 |
| CR | 13 |
| DQUOTE | 22 |
| SPACE | 32 |
| PLUS SIGN | 43 |
| COMMA | 44 |
| HYPHEN-MINUS | 45 |
| PERIOD | 46 |
| SOLIDUS | 47 |
| COLON | 58 |
| SEMICOLON | 59 |
| LATIN CAPITAL LETTER N | 78 |
| LATIN CAPITAL LETTER T | 84 |
| LATIN CAPITAL LETTER X | 88 |
| LATIN CAPITAL LETTER Z | 90 |
| BACKSLASH | 92 |
| LATIN SMALL LETTER N | 110 |
+------------------------+-------------------+
2.2. Related Memos 2.2. Related Memos
Implementers will need to be familiar with several other memos that, Implementers will need to be familiar with several other memos that,
along with this memo, form a framework for Internet calendaring and along with this memo, form a framework for Internet calendaring and
scheduling standards. This memo specifies a core specification of scheduling standards. This memo specifies a core specification of
objects, value types, properties and property parameters. objects, value types, properties, and property parameters.
o iTIP [I-D.ietf-calsify-2446bis] specifies an interoperability o iTIP [2446bis] specifies an interoperability protocol for
protocol for scheduling between different implementations; scheduling between different implementations;
o iMIP [I-D.ietf-calsify-rfc2447bis] specifies an Internet email o iCalendar Message-Based Interoperability Protocol (iMIP) [2447bis]
binding for [I-D.ietf-calsify-2446bis]. specifies an Internet email binding for [2446bis].
This memo does not attempt to repeat the specification of concepts or This memo does not attempt to repeat the specification of concepts or
definitions from these other memos. Where possible, references are definitions from these other memos. Where possible, references are
made to the memo that provides for the specification of these made to the memo that provides for the specification of these
concepts or definitions. concepts or definitions.
3. iCalendar Object Specification 3. iCalendar Object Specification
The following sections define the details of a Calendaring and The following sections define the details of a Calendaring and
Scheduling Core Object Specification. The Calendaring and Scheduling Scheduling Core Object Specification. The Calendaring and Scheduling
Core Object is a collection of calendaring and scheduling Core Object is a collection of calendaring and scheduling
information. Typically, this information will consist of an information. Typically, this information will consist of an
iCalendar stream with one or more iCalendar objects. The body of the iCalendar stream with one or more iCalendar objects. The body of the
RFC 5545 iCalendar September 2009
iCalendar object consists of a sequence of calendar properties and iCalendar object consists of a sequence of calendar properties and
one or more calendar components. one or more calendar components.
Section 3.1 defines the content line format; Section 3.2 defines the Section 3.1 defines the content line format; Section 3.2 defines the
property parameter format; Section 3.3 defines the data types for property parameter format; Section 3.3 defines the data types for
property values; Section 3.4 defines the iCalendar object format; property values; Section 3.4 defines the iCalendar object format;
Section 3.5 defines the iCalendar property format; Section 3.6 Section 3.5 defines the iCalendar property format; Section 3.6
defines the calendar component format; Section 3.7 defines calendar defines the calendar component format; Section 3.7 defines calendar
properties; and Section 3.8 defines calendar component properties. properties; and Section 3.8 defines calendar component properties.
This information is intended to be an integral part of the MIME This information is intended to be an integral part of the MIME
content type registration. In addition, this information can be used content type registration. In addition, this information can be used
independent of such content registration. In particular, this memo independent of such content registration. In particular, this memo
has direct applicability for use as a calendaring and scheduling has direct applicability for use as a calendaring and scheduling
exchange format in file-, memory- or network-based transport exchange format in file-, memory-, or network-based transport
mechanisms. mechanisms.
3.1. Content Lines 3.1. Content Lines
The iCalendar object is organized into individual lines of text, The iCalendar object is organized into individual lines of text,
called content lines. Content lines are delimited by a line break, called content lines. Content lines are delimited by a line break,
which is a CRLF sequence (US-ASCII decimal 13, followed by US-ASCII which is a CRLF sequence (CR character followed by LF character).
decimal 10).
Lines of text SHOULD NOT be longer than 75 octets, excluding the line Lines of text SHOULD NOT be longer than 75 octets, excluding the line
break. Long content lines SHOULD be split into a multiple line break. Long content lines SHOULD be split into a multiple line
representations using a line "folding" technique. That is, a long representations using a line "folding" technique. That is, a long
line can be split between any two characters by inserting a CRLF line can be split between any two characters by inserting a CRLF
immediately followed by a single linear white space character (i.e., immediately followed by a single linear white-space character (i.e.,
SPACE, US-ASCII decimal 32 or HTAB, US-ASCII decimal 9). Any SPACE or HTAB). Any sequence of CRLF followed immediately by a
sequence of CRLF followed immediately by a single linear white space single linear white-space character is ignored (i.e., removed) when
character is ignored (i.e., removed) when processing the content processing the content type.
type.
For example the line: For example, the line:
DESCRIPTION:This is a long description that exists on a long line. DESCRIPTION:This is a long description that exists on a long line.
Can be represented as: Can be represented as:
DESCRIPTION:This is a lo DESCRIPTION:This is a lo
ng description ng description
that exists on a long line. that exists on a long line.
The process of moving from this folded multiple line representation The process of moving from this folded multiple-line representation
to its single line representation is called "unfolding". Unfolding to its single-line representation is called "unfolding". Unfolding
is accomplished by removing the CRLF character and the linear white is accomplished by removing the CRLF and the linear white-space
space character that immediately follows. character that immediately follows.
RFC 5545 iCalendar September 2009
When parsing a content line, folded lines MUST first be unfolded When parsing a content line, folded lines MUST first be unfolded
according to the unfolding procedure described above. according to the unfolding procedure described above.
Note: It is possible for very simple implementations to generate Note: It is possible for very simple implementations to generate
improperly folded lines in the middle of a UTF-8 multi-octet improperly folded lines in the middle of a UTF-8 multi-octet
sequence. For this reason, implementations need to unfold lines sequence. For this reason, implementations need to unfold lines
in such a way to properly restore the original sequence. in such a way to properly restore the original sequence.
The content information associated with an iCalendar object is The content information associated with an iCalendar object is
formatted using a syntax similar to that defined by [RFC2425]. That formatted using a syntax similar to that defined by [RFC2425]. That
is, the content information consists of CRLF-separated content lines. is, the content information consists of CRLF-separated content lines.
The following notation defines the lines of content in an iCalendar The following notation defines the lines of content in an iCalendar
object: object:
contentline = name *(";" param ) ":" value CRLF contentline = name *(";" param ) ":" value CRLF
; This ABNF is just a general definition for an initial parsing ; This ABNF is just a general definition for an initial parsing
; of the content line into its property name, parameter list, ; of the content line into its property name, parameter list,
; and value string ; and value string
; When parsing a content line, folded lines MUST first ; When parsing a content line, folded lines MUST first
; be unfolded according to the unfolding procedure ; be unfolded according to the unfolding procedure
; described above. When generating a content line, lines ; described above. When generating a content line, lines
; longer than 75 octets SHOULD be folded according to ; longer than 75 octets SHOULD be folded according to
; the folding procedure described above. ; the folding procedure described above.
name = iana-token / x-name name = iana-token / x-name
iana-token = 1*(ALPHA / DIGIT / "-") iana-token = 1*(ALPHA / DIGIT / "-")
; iCalendar identifier registered with IANA ; iCalendar identifier registered with IANA
x-name = "X-" [vendorid "-"] 1*(ALPHA / DIGIT / "-") x-name = "X-" [vendorid "-"] 1*(ALPHA / DIGIT / "-")
; Reserved for experimental use. ; Reserved for experimental use.
vendorid = 3*(ALPHA / DIGIT) vendorid = 3*(ALPHA / DIGIT)
; Vendor identification ; Vendor identification
param = param-name "=" param-value *("," param-value) param = param-name "=" param-value *("," param-value)
; Each property defines the specific ABNF for the parameters ; Each property defines the specific ABNF for the parameters
; allowed on the property. Refer to specific properties for ; allowed on the property. Refer to specific properties for
; precise parameter ABNF. ; precise parameter ABNF.
param-name = iana-token / x-name param-name = iana-token / x-name
param-value = paramtext / quoted-string param-value = paramtext / quoted-string
paramtext = *SAFE-CHAR paramtext = *SAFE-CHAR
value = *VALUE-CHAR RFC 5545 iCalendar September 2009
quoted-string = DQUOTE *QSAFE-CHAR DQUOTE value = *VALUE-CHAR
QSAFE-CHAR = WSP / %x21 / %x23-7E / NON-US-ASCII quoted-string = DQUOTE *QSAFE-CHAR DQUOTE
; Any character except CONTROL and DQUOTE
SAFE-CHAR = WSP / %x21 / %x23-2B / %x2D-39 / %x3C-7E QSAFE-CHAR = WSP / %x21 / %x23-7E / NON-US-ASCII
/ NON-US-ASCII ; Any character except CONTROL and DQUOTE
; Any character except CONTROL, DQUOTE, ";", ":", ","
VALUE-CHAR = WSP / %x21-7E / NON-US-ASCII SAFE-CHAR = WSP / %x21 / %x23-2B / %x2D-39 / %x3C-7E
; Any textual character / NON-US-ASCII
; Any character except CONTROL, DQUOTE, ";", ":", ","
NON-US-ASCII = UTF8-2 / UTF8-3 / UTF8-4 VALUE-CHAR = WSP / %x21-7E / NON-US-ASCII
; UTF8-2, UTF8-3, and UTF8-4 are defined in [RFC3629] ; Any textual character
CONTROL = %x00-08 / %x0A-1F / %x7F NON-US-ASCII = UTF8-2 / UTF8-3 / UTF8-4
; All the controls except HTAB ; UTF8-2, UTF8-3, and UTF8-4 are defined in [RFC3629]
CONTROL = %x00-08 / %x0A-1F / %x7F
; All the controls except HTAB
The property value component of a content line has a format that is The property value component of a content line has a format that is
property specific. Refer to the section describing each property for property specific. Refer to the section describing each property for
a definition of this format. a definition of this format.
All names of properties, property parameters, enumerated property All names of properties, property parameters, enumerated property
values and property parameter values are case-insensitive. However, values and property parameter values are case-insensitive. However,
all other property values are case-sensitive, unless otherwise all other property values are case-sensitive, unless otherwise
stated. stated.
3.1.1. List and Field Separators 3.1.1. List and Field Separators
Some properties and parameters allow a list of values. Values in a Some properties and parameters allow a list of values. Values in a
list of values MUST be separated by a COMMA character (US-ASCII list of values MUST be separated by a COMMA character. There is no
decimal 44). There is no significance to the order of values in a significance to the order of values in a list. For those parameter
list. For those parameter values (such as those that specify URI values (such as those that specify URI values) that are specified in
values) that are specified in quoted-strings, the individual quoted- quoted-strings, the individual quoted-strings are separated by a
strings are separated by a COMMA character (US-ASCII decimal 44). COMMA character.
Some property values are defined in terms of multiple parts. These Some property values are defined in terms of multiple parts. These
structured property values MUST have their value parts separated by a structured property values MUST have their value parts separated by a
SEMICOLON character (US-ASCII decimal 59). SEMICOLON character.
Some properties allow a list of parameters. Each property parameter Some properties allow a list of parameters. Each property parameter
in a list of property parameters MUST be separated by a SEMICOLON in a list of property parameters MUST be separated by a SEMICOLON
character (US-ASCII decimal 59). character.
Property parameters with values containing a COLON character (US- RFC 5545 iCalendar September 2009
ASCII decimal 58), a SEMICOLON character (US-ASCII decimal 59) or a
COMMA character (US-ASCII decimal 44) MUST be placed in quoted text.
For example, in the following properties a SEMICOLON is used to Property parameters with values containing a COLON character, a
separate property parameters from each other, and a COMMA is used to SEMICOLON character or a COMMA character MUST be placed in quoted
separate property values in a value list. text.
ATTENDEE;RSVP=TRUE;ROLE=REQ-PARTICIPANT:mailto: For example, in the following properties, a SEMICOLON is used to
jsmith@example.com separate property parameters from each other and a COMMA character is
used to separate property values in a value list.
RDATE;VALUE=DATE:19970304,19970504,19970704,19970904 ATTENDEE;RSVP=TRUE;ROLE=REQ-PARTICIPANT:mailto:
jsmith@example.com
RDATE;VALUE=DATE:19970304,19970504,19970704,19970904
3.1.2. Multiple Values 3.1.2. Multiple Values
Some properties defined in the iCalendar object can have multiple Some properties defined in the iCalendar object can have multiple
values. The general rule for encoding multi-valued items is to values. The general rule for encoding multi-valued items is to
simply create a new content line for each value, including the simply create a new content line for each value, including the
property name. However, it should be noted that some properties property name. However, it should be noted that some properties
support encoding multiple values in a single property by separating support encoding multiple values in a single property by separating
the values with a COMMA character (US-ASCII decimal 44). Individual the values with a COMMA character. Individual property definitions
property definitions should be consulted for determining whether a should be consulted for determining whether a specific property
specific property allows multiple values and in which of these two allows multiple values and in which of these two forms. Multi-valued
forms. Multi-valued properties MUST NOT be used to specify multiple properties MUST NOT be used to specify multiple language variants of
language variants of the same value. Calendar applications SHOULD the same value. Calendar applications SHOULD display all values.
display all values.
3.1.3. Binary Content 3.1.3. Binary Content
Binary content information in an iCalendar object SHOULD be Binary content information in an iCalendar object SHOULD be
referenced using a URI within a property value. That is the binary referenced using a URI within a property value. That is, the binary
content information SHOULD be placed in an external MIME entity that content information SHOULD be placed in an external MIME entity that
can be referenced by a URI from within the iCalendar object. In can be referenced by a URI from within the iCalendar object. In
applications where this is not feasible, binary content information applications where this is not feasible, binary content information
can be included within an iCalendar object, but only after first can be included within an iCalendar object, but only after first
encoding it into text using the "BASE64" encoding method defined in encoding it into text using the "BASE64" encoding method defined in
[RFC4648]. Inline binary content SHOULD only be used in applications [RFC4648]. Inline binary content SHOULD only be used in applications
whose special circumstances demand that an iCalendar object be whose special circumstances demand that an iCalendar object be
expressed as a single entity. A property containing inline binary expressed as a single entity. A property containing inline binary
content information MUST specify the "ENCODING" property parameter. content information MUST specify the "ENCODING" property parameter.
Binary content information placed external to the iCalendar object Binary content information placed external to the iCalendar object
MUST be referenced by a uniform resource identifier (URI). MUST be referenced by a uniform resource identifier (URI).
The following example specifies an "ATTACH" property that references The following example specifies an "ATTACH" property that references
an attachment external to the iCalendar object with a URI reference: an attachment external to the iCalendar object with a URI reference:
ATTACH:http://example.com/public/quarterly-report.doc ATTACH:http://example.com/public/quarterly-report.doc
RFC 5545 iCalendar September 2009
The following example specifies an "ATTACH" property with inline The following example specifies an "ATTACH" property with inline
binary encoded content information: binary encoded content information:
ATTACH;FMTTYPE=text/plain;ENCODING=BASE64;VALUE=BINARY:VGhlIH ATTACH;FMTTYPE=text/plain;ENCODING=BASE64;VALUE=BINARY:VGhlIH
F1aWNrIGJyb3duIGZveCBqdW1wcyBvdmVyIHRoZSBsYXp5IGRvZy4 F1aWNrIGJyb3duIGZveCBqdW1wcyBvdmVyIHRoZSBsYXp5IGRvZy4
3.1.4. Character Set 3.1.4. Character Set
There is not a property parameter to declare the charset used in a There is not a property parameter to declare the charset used in a
property value. The default charset for an iCalendar stream is UTF-8 property value. The default charset for an iCalendar stream is UTF-8
as defined in [RFC3629]. as defined in [RFC3629].
The "charset" Content-Type parameter MUST be used in MIME transports The "charset" Content-Type parameter MUST be used in MIME transports
to specify the charset being used. to specify the charset being used.
3.2. Property Parameters 3.2. Property Parameters
A property can have attributes associated with it. These "property A property can have attributes with which it is associated. These
parameters" contain meta-information about the property or the "property parameters" contain meta-information about the property or
property value. Property parameters are provided to specify such the property value. Property parameters are provided to specify such
information as the location of an alternate text representation for a information as the location of an alternate text representation for a
property value, the language of a text property value, the value type property value, the language of a text property value, the value type
of the property value and other attributes. of the property value, and other attributes.
Property parameter values that contain the COLON (US-ASCII decimal Property parameter values that contain the COLON, SEMICOLON, or COMMA
58), SEMICOLON (US-ASCII decimal 59) or COMMA (US-ASCII decimal 44)
character separators MUST be specified as quoted-string text values. character separators MUST be specified as quoted-string text values.
Property parameter values MUST NOT contain the DQUOTE (US-ASCII Property parameter values MUST NOT contain the DQUOTE character. The
decimal 22) character. The DQUOTE (US-ASCII decimal 22) character is DQUOTE character is used as a delimiter for parameter values that
used as a delimiter for parameter values that contain restricted contain restricted characters or URI text. For example:
characters or URI text. For example:
DESCRIPTION;ALTREP="cid:part1.0001@example.org":The Fall'98 Wild DESCRIPTION;ALTREP="cid:part1.0001@example.org":The Fall'98 Wild
Wizards Conference - - Las Vegas\, NV\, USA Wizards Conference - - Las Vegas\, NV\, USA
Property parameter values that are not in quoted strings are case Property parameter values that are not in quoted-strings are case-
insensitive. insensitive.
The general property parameters defined by this memo are defined by The general property parameters defined by this memo are defined by
the following notation: the following notation:
icalparameter = altrepparam ; Alternate text representation RFC 5545 iCalendar September 2009
/ cnparam ; Common name
/ cutypeparam ; Calendar user type
/ delfromparam ; Delegator
/ deltoparam ; Delegatee
/ dirparam ; Directory entry
/ encodingparam ; Inline encoding
/ fmttypeparam ; Format type
/ fbtypeparam ; Free/busy time type
/ languageparam ; Language for text
/ memberparam ; Group or list membership
/ partstatparam ; Participation status
/ rangeparam ; Recurrence identifier range
/ trigrelparam ; Alarm trigger relationship
/ reltypeparam ; Relationship type
/ roleparam ; Participation role
/ rsvpparam ; RSVP expectation
/ sentbyparam ; Sent by
/ tzidparam ; Reference to time zone object
/ valuetypeparam ; Property value data type
/ other-param
other-param = (iana-param / x-param) icalparameter = altrepparam ; Alternate text representation
/ cnparam ; Common name
/ cutypeparam ; Calendar user type
/ delfromparam ; Delegator
/ deltoparam ; Delegatee
/ dirparam ; Directory entry
/ encodingparam ; Inline encoding
/ fmttypeparam ; Format type
/ fbtypeparam ; Free/busy time type
/ languageparam ; Language for text
/ memberparam ; Group or list membership
/ partstatparam ; Participation status
/ rangeparam ; Recurrence identifier range
/ trigrelparam ; Alarm trigger relationship
/ reltypeparam ; Relationship type
/ roleparam ; Participation role
/ rsvpparam ; RSVP expectation
/ sentbyparam ; Sent by
/ tzidparam ; Reference to time zone object
/ valuetypeparam ; Property value data type
/ other-param
iana-param = iana-token "=" param-value *("," param-value) other-param = (iana-param / x-param)
; Some other IANA registered iCalendar parameter.
x-param = x-name "=" param-value *("," param-value) iana-param = iana-token "=" param-value *("," param-value)
; A non-standard, experimental parameter. ; Some other IANA-registered iCalendar parameter.
Applications MUST ignore x-param and iana-param value they don't x-param = x-name "=" param-value *("," param-value)
recognized. ; A non-standard, experimental parameter.
Applications MUST ignore x-param and iana-param values they don't
recognize.
3.2.1. Alternate Text Representation 3.2.1. Alternate Text Representation
Parameter Name: ALTREP Parameter Name: ALTREP
Purpose: To specify an alternate text representation for the Purpose: To specify an alternate text representation for the
property value. property value.
Format Definition: This property parameter is defined by the Format Definition: This property parameter is defined by the
following notation: following notation:
altrepparam = "ALTREP" "=" DQUOTE uri DQUOTE altrepparam = "ALTREP" "=" DQUOTE uri DQUOTE
Description: This parameter specifies a URI that points to an Description: This parameter specifies a URI that points to an
alternate representation for a textual property value. A property alternate representation for a textual property value. A property
specifying this parameter MUST also include a value that reflects specifying this parameter MUST also include a value that reflects
RFC 5545 iCalendar September 2009
the default representation of the text value. The URI parameter the default representation of the text value. The URI parameter
value MUST be specified in a quoted-string. value MUST be specified in a quoted-string.
Note: While there is no restriction imposed on the URI schemes Note: While there is no restriction imposed on the URI schemes
allowed for this parameter, CID [RFC2392], HTTP [RFC2616], and allowed for this parameter, Content Identifier (CID) [RFC2392],
HTTPS [RFC2818] are the URI schemes most commonly used by HTTP [RFC2616], and HTTPS [RFC2818] are the URI schemes most
current implementations. commonly used by current implementations.
Example: Example:
DESCRIPTION;ALTREP="CID:part3.msg.970415T083000@example.com": DESCRIPTION;ALTREP="CID:part3.msg.970415T083000@example.com":
Project XYZ Review Meeting will include the following agenda Project XYZ Review Meeting will include the following agenda
items: (a) Market Overview\, (b) Finances\, (c) Project Man items: (a) Market Overview\, (b) Finances\, (c) Project Man
agement agement
The "ALTREP" property parameter value might point to a "text/html" The "ALTREP" property parameter value might point to a "text/html"
content portion. content portion.
Content-Type:text/html Content-Type:text/html
Content-Id:<part3.msg.970415T083000@example.com> Content-Id:<part3.msg.970415T083000@example.com>
<html> <html>
<head> <head>
<title></title> <title></title>
</head> </head>
<body> <body>
<p> <p>
<b>Project XYZ Review Meeting</b> will include <b>Project XYZ Review Meeting</b> will include
the following agenda items: the following agenda items:
<ol> <ol>
<li>Market Overview</li> <li>Market Overview</li>
<li>Finances</li> <li>Finances</li>
<li>Project Management</li> <li>Project Management</li>
</ol> </ol>
</p> </p>
</body> </body>
</html> </html>
3.2.2. Common Name 3.2.2. Common Name
Parameter Name: CN Parameter Name: CN
Purpose: To specify the common name to be associated with the Purpose: To specify the common name to be associated with the
calendar user specified by the property. calendar user specified by the property.
Format Definition: This property parameter is defined by the Format Definition: This property parameter is defined by the
following notation: following notation:
cnparam = "CN" "=" param-value RFC 5545 iCalendar September 2009
cnparam = "CN" "=" param-value
Description: This parameter can be specified on properties with a Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. The parameter specifies the common name CAL-ADDRESS value type. The parameter specifies the common name
to be associated with the calendar user specified by the property. to be associated with the calendar user specified by the property.
The parameter value is text. The parameter value can be used for The parameter value is text. The parameter value can be used for
display text to be associated with the calendar address specified display text to be associated with the calendar address specified
by the property. by the property.
Example: Example:
ORGANIZER;CN="John Smith":mailto:jsmith@example.com ORGANIZER;CN="John Smith":mailto:jsmith@example.com
3.2.3. Calendar User Type 3.2.3. Calendar User Type
Parameter Name: CUTYPE Parameter Name: CUTYPE
Purpose: To specify the type of calendar user specified by the Purpose: To identify the type of calendar user specified by the
property. property.
Format Definition: This property parameter is defined by the Format Definition: This property parameter is defined by the
following notation: following notation:
cutypeparam = "CUTYPE" "=" cutypeparam = "CUTYPE" "="
("INDIVIDUAL" ; An individual ("INDIVIDUAL" ; An individual
/ "GROUP" ; A group of individuals / "GROUP" ; A group of individuals
/ "RESOURCE" ; A physical resource / "RESOURCE" ; A physical resource
/ "ROOM" ; A room resource / "ROOM" ; A room resource
/ "UNKNOWN" ; Otherwise not known / "UNKNOWN" ; Otherwise not known
/ x-name ; Experimental type / x-name ; Experimental type
/ iana-token) ; Other IANA registered / iana-token) ; Other IANA-registered
; type ; type
; Default is INDIVIDUAL ; Default is INDIVIDUAL
Description: This parameter can be specified on properties with a Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. The parameter identifies the type of CAL-ADDRESS value type. The parameter identifies the type of
calendar user specified by the property. If not specified on a calendar user specified by the property. If not specified on a
property that allows this parameter, the default is INDIVIDUAL. property that allows this parameter, the default is INDIVIDUAL.
Applications MUST treat x-name and iana-token value they don't Applications MUST treat x-name and iana-token values they don't
recognized the same way as they would the UNKNOWN value. recognize the same way as they would the UNKNOWN value.
Example: Example:
ATTENDEE;CUTYPE=GROUP:mailto:ietf-calsch@example.org ATTENDEE;CUTYPE=GROUP:mailto:ietf-calsch@example.org
RFC 5545 iCalendar September 2009
3.2.4. Delegators 3.2.4. Delegators
Parameter Name: DELEGATED-FROM Parameter Name: DELEGATED-FROM
Purpose: To specify the calendar users that have delegated their Purpose: To specify the calendar users that have delegated their
participation to the calendar user specified by the property. participation to the calendar user specified by the property.
Format Definition: This property parameter is defined by the Format Definition: This property parameter is defined by the
following notation: following notation:
delfromparam = "DELEGATED-FROM" "=" DQUOTE cal-address delfromparam = "DELEGATED-FROM" "=" DQUOTE cal-address
DQUOTE *("," DQUOTE cal-address DQUOTE) DQUOTE *("," DQUOTE cal-address DQUOTE)
Description: This parameter can be specified on properties with a Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. This parameter specifies those calendar CAL-ADDRESS value type. This parameter specifies those calendar
users that have delegated their participation in a group scheduled users that have delegated their participation in a group-scheduled
event or to-do to the calendar user specified by the property. event or to-do to the calendar user specified by the property.
The individual calendar address parameter values MUST each be The individual calendar address parameter values MUST each be
specified in a quoted-string. specified in a quoted-string.
Example: Example:
ATTENDEE;DELEGATED-FROM="mailto:jsmith@example.com":mailto: ATTENDEE;DELEGATED-FROM="mailto:jsmith@example.com":mailto:
jdoe@example.com jdoe@example.com
3.2.5. Delegatees 3.2.5. Delegatees
Parameter Name: DELEGATED-TO Parameter Name: DELEGATED-TO
Purpose: To specify the calendar users to whom the calendar user Purpose: To specify the calendar users to whom the calendar user
specified by the property has delegated participation. specified by the property has delegated participation.
Format Definition: This property parameter is defined by the Format Definition: This property parameter is defined by the
following notation: following notation:
deltoparam = "DELEGATED-TO" "=" DQUOTE cal-address DQUOTE deltoparam = "DELEGATED-TO" "=" DQUOTE cal-address DQUOTE
*("," DQUOTE cal-address DQUOTE) *("," DQUOTE cal-address DQUOTE)
Description: This parameter can be specified on properties with a Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. This parameter specifies those calendar CAL-ADDRESS value type. This parameter specifies those calendar
users whom have been delegated participation in a group scheduled users whom have been delegated participation in a group-scheduled
event or to-do by the calendar user specified by the property. event or to-do by the calendar user specified by the property.
The individual calendar address parameter values MUST each be The individual calendar address parameter values MUST each be
specified in a quoted-string. specified in a quoted-string.
RFC 5545 iCalendar September 2009
Example: Example:
ATTENDEE;DELEGATED-TO="mailto:jdoe@example.com","mailto:jqpublic ATTENDEE;DELEGATED-TO="mailto:jdoe@example.com","mailto:jqpublic
@example.com":mailto:jsmith@example.com @example.com":mailto:jsmith@example.com
3.2.6. Directory Entry Reference 3.2.6. Directory Entry Reference
Parameter Name: DIR Parameter Name: DIR
Purpose: To specify reference to a directory entry associated with Purpose: To specify reference to a directory entry associated with
the calendar user specified by the property. the calendar user specified by the property.
Format Definition: This property parameter is defined by the Format Definition: This property parameter is defined by the
following notation: following notation:
dirparam = "DIR" "=" DQUOTE uri DQUOTE dirparam = "DIR" "=" DQUOTE uri DQUOTE
Description: This parameter can be specified on properties with a Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. The parameter specifies a reference to CAL-ADDRESS value type. The parameter specifies a reference to
the directory entry associated with the calendar user specified by the directory entry associated with the calendar user specified by
the property. The parameter value is a URI. The URI parameter the property. The parameter value is a URI. The URI parameter
value MUST be specified in a quoted-string. value MUST be specified in a quoted-string.
Note: While there is no restriction imposed on the URI schemes Note: While there is no restriction imposed on the URI schemes
allowed for this parameter, CID [RFC2392], DATA [RFC2397], FILE allowed for this parameter, CID [RFC2392], DATA [RFC2397], FILE
[RFC1738], FTP [RFC1738], HTTP [RFC2616], HTTPS [RFC2818], LDAP [RFC1738], FTP [RFC1738], HTTP [RFC2616], HTTPS [RFC2818], LDAP
[RFC4516], and MID [RFC2392] are the URI schemes most commonly [RFC4516], and MID [RFC2392] are the URI schemes most commonly
used by current implementations. used by current implementations.
Example: Example:
ORGANIZER;DIR="ldap://example.com:6666/o=ABC%20Industries, ORGANIZER;DIR="ldap://example.com:6666/o=ABC%20Industries,
c=US???(cn=Jim%20Dolittle)":mailto:jimdo@example.com c=US???(cn=Jim%20Dolittle)":mailto:jimdo@example.com
3.2.7. Inline Encoding 3.2.7. Inline Encoding
Parameter Name: ENCODING Parameter Name: ENCODING
Purpose: To specify an alternate inline encoding for the property Purpose: To specify an alternate inline encoding for the property
value. value.
Format Definition: This property parameter is defined by the Format Definition: This property parameter is defined by the
following notation: following notation:
encodingparam = "ENCODING" "=" RFC 5545 iCalendar September 2009
( "8BIT"
; "8bit" text encoding is defined in [RFC2045] encodingparam = "ENCODING" "="
/ "BASE64" ( "8BIT"
; "BASE64" binary encoding format is defined in [RFC4648] ; "8bit" text encoding is defined in [RFC2045]
) / "BASE64"
; "BASE64" binary encoding format is defined in [RFC4648]
)
Description: This property parameter identifies the inline encoding Description: This property parameter identifies the inline encoding
used in a property value. The default encoding is "8BIT", used in a property value. The default encoding is "8BIT",
corresponding to a property value consisting of text. The corresponding to a property value consisting of text. The
"BASE64" encoding type corresponds to a property value encoded "BASE64" encoding type corresponds to a property value encoded
using the "BASE64" encoding defined in [RFC2045]. using the "BASE64" encoding defined in [RFC2045].
If the value type parameter is ";VALUE=BINARY", then the inline If the value type parameter is ";VALUE=BINARY", then the inline
encoding parameter MUST be specified with the value encoding parameter MUST be specified with the value
";ENCODING=BASE64". ";ENCODING=BASE64".
Example: Example:
ATTACH;FMTTYPE=text/plain;ENCODING=BASE64;VALUE=BINARY:TG9yZW ATTACH;FMTTYPE=text/plain;ENCODING=BASE64;VALUE=BINARY:TG9yZW
0gaXBzdW0gZG9sb3Igc2l0IGFtZXQsIGNvbnNlY3RldHVyIGFkaXBpc2ljaW 0gaXBzdW0gZG9sb3Igc2l0IGFtZXQsIGNvbnNlY3RldHVyIGFkaXBpc2ljaW
5nIGVsaXQsIHNlZCBkbyBlaXVzbW9kIHRlbXBvciBpbmNpZGlkdW50IHV0IG 5nIGVsaXQsIHNlZCBkbyBlaXVzbW9kIHRlbXBvciBpbmNpZGlkdW50IHV0IG
xhYm9yZSBldCBkb2xvcmUgbWFnbmEgYWxpcXVhLiBVdCBlbmltIGFkIG1pbm xhYm9yZSBldCBkb2xvcmUgbWFnbmEgYWxpcXVhLiBVdCBlbmltIGFkIG1pbm
ltIHZlbmlhbSwgcXVpcyBub3N0cnVkIGV4ZXJjaXRhdGlvbiB1bGxhbWNvIG ltIHZlbmlhbSwgcXVpcyBub3N0cnVkIGV4ZXJjaXRhdGlvbiB1bGxhbWNvIG
xhYm9yaXMgbmlzaSB1dCBhbGlxdWlwIGV4IGVhIGNvbW1vZG8gY29uc2VxdW xhYm9yaXMgbmlzaSB1dCBhbGlxdWlwIGV4IGVhIGNvbW1vZG8gY29uc2VxdW
F0LiBEdWlzIGF1dGUgaXJ1cmUgZG9sb3IgaW4gcmVwcmVoZW5kZXJpdCBpbi F0LiBEdWlzIGF1dGUgaXJ1cmUgZG9sb3IgaW4gcmVwcmVoZW5kZXJpdCBpbi
B2b2x1cHRhdGUgdmVsaXQgZXNzZSBjaWxsdW0gZG9sb3JlIGV1IGZ1Z2lhdC B2b2x1cHRhdGUgdmVsaXQgZXNzZSBjaWxsdW0gZG9sb3JlIGV1IGZ1Z2lhdC
BudWxsYSBwYXJpYXR1ci4gRXhjZXB0ZXVyIHNpbnQgb2NjYWVjYXQgY3VwaW BudWxsYSBwYXJpYXR1ci4gRXhjZXB0ZXVyIHNpbnQgb2NjYWVjYXQgY3VwaW
RhdGF0IG5vbiBwcm9pZGVudCwgc3VudCBpbiBjdWxwYSBxdWkgb2ZmaWNpYS RhdGF0IG5vbiBwcm9pZGVudCwgc3VudCBpbiBjdWxwYSBxdWkgb2ZmaWNpYS
BkZXNlcnVudCBtb2xsaXQgYW5pbSBpZCBlc3QgbGFib3J1bS4= BkZXNlcnVudCBtb2xsaXQgYW5pbSBpZCBlc3QgbGFib3J1bS4=
3.2.8. Format Type 3.2.8. Format Type
Parameter Name: FMTTYPE Parameter Name: FMTTYPE
Purpose: To specify the content type of a referenced object. Purpose: To specify the content type of a referenced object.
Format Definition: This property parameter is defined by the Format Definition: This property parameter is defined by the
following notation: following notation:
fmttypeparam = "FMTTYPE" "=" type-name "/" subtype-name fmttypeparam = "FMTTYPE" "=" type-name "/" subtype-name
; Where "type-name" and "subtype-name" are ; Where "type-name" and "subtype-name" are
; defined in section 4.2 of [RFC4288] ; defined in Section 4.2 of [RFC4288].
Description: This parameter can be specified on properties that are Description: This parameter can be specified on properties that are
used to reference an object. The parameter specifies the media used to reference an object. The parameter specifies the media
type [RFC4288] of the referenced object. For example, on the type [RFC4288] of the referenced object. For example, on the
"ATTACH" property, a FTP type URI value does not, by itself, "ATTACH" property, an FTP type URI value does not, by itself,
RFC 5545 iCalendar September 2009
necessarily convey the type of content associated with the necessarily convey the type of content associated with the
resource. The parameter value MUST be the text for either an IANA resource. The parameter value MUST be the text for either an
registered media type or a non-standard media type. IANA-registered media type or a non-standard media type.
Example: Example:
ATTACH;FMTTYPE=application/msword:ftp://example.com/pub/docs/ ATTACH;FMTTYPE=application/msword:ftp://example.com/pub/docs/
agenda.doc agenda.doc
3.2.9. Free/Busy Time Type 3.2.9. Free/Busy Time Type
Parameter Name: FBTYPE Parameter Name: FBTYPE
Purpose: To specify the free or busy time type. Purpose: To specify the free or busy time type.
Format Definition: This property parameter is defined by the Format Definition: This property parameter is defined by the
following notation: following notation:
fbtypeparam = "FBTYPE" "=" ("FREE" / "BUSY" fbtypeparam = "FBTYPE" "=" ("FREE" / "BUSY"
/ "BUSY-UNAVAILABLE" / "BUSY-TENTATIVE" / "BUSY-UNAVAILABLE" / "BUSY-TENTATIVE"
/ x-name / x-name
; Some experimental iCalendar free busy type. ; Some experimental iCalendar free/busy type.
/ iana-token) / iana-token)
; Some other IANA registered iCalendar free busy type. ; Some other IANA-registered iCalendar free/busy type.
Description: This parameter specifies the free or busy time type. Description: This parameter specifies the free or busy time type.
The value FREE indicates that the time interval is free for The value FREE indicates that the time interval is free for
scheduling. The value BUSY indicates that the time interval is scheduling. The value BUSY indicates that the time interval is
busy because one or more events have been scheduled for that busy because one or more events have been scheduled for that
interval. The value BUSY-UNAVAILABLE indicates that the time interval. The value BUSY-UNAVAILABLE indicates that the time
interval is busy and that the interval can not be scheduled. The interval is busy and that the interval can not be scheduled. The
value BUSY-TENTATIVE indicates that the time interval is busy value BUSY-TENTATIVE indicates that the time interval is busy
because one or more events have been tentatively scheduled for because one or more events have been tentatively scheduled for
that interval. If not specified on a property that allows this that interval. If not specified on a property that allows this
parameter, the default is BUSY. Applications MUST treat x-name parameter, the default is BUSY. Applications MUST treat x-name
and iana-token value they don't recognized the same way as they and iana-token values they don't recognize the same way as they
would the BUSY value. would the BUSY value.
Example: The following is an example of this parameter on a Example: The following is an example of this parameter on a
"FREEBUSY" property. "FREEBUSY" property.
FREEBUSY;FBTYPE=BUSY:19980415T133000Z/19980415T170000Z FREEBUSY;FBTYPE=BUSY:19980415T133000Z/19980415T170000Z
RFC 5545 iCalendar September 2009
3.2.10. Language 3.2.10. Language
Parameter Name: LANGUAGE Parameter Name: LANGUAGE
Purpose: To specify the language for text values in a property or Purpose: To specify the language for text values in a property or
property parameter. property parameter.
Format Definition: This property parameter is defined by the Format Definition: This property parameter is defined by the
following notation: following notation:
languageparam = "LANGUAGE" "=" language languageparam = "LANGUAGE" "=" language
language = Language-Tag language = Language-Tag
; As defined in [RFC4646] ; As defined in [RFC5646].
Description: This parameter identifies the language of the text in Description: This parameter identifies the language of the text in
the property value and of all property parameter values of the the property value and of all property parameter values of the
property. The value of the "LANGUAGE" property parameter is that property. The value of the "LANGUAGE" property parameter is that
defined in [RFC4646]. defined in [RFC5646].
For transport in a MIME entity, the Content-Language header field For transport in a MIME entity, the Content-Language header field
can be used to set the default language for the entire body part. can be used to set the default language for the entire body part.
Otherwise, no default language is assumed. Otherwise, no default language is assumed.
Example: The following are examples of this parameter on the Example: The following are examples of this parameter on the
"SUMMARY" and "LOCATION" properties: "SUMMARY" and "LOCATION" properties:
SUMMARY;LANGUAGE=en-US:Company Holiday Party SUMMARY;LANGUAGE=en-US:Company Holiday Party
LOCATION;LANGUAGE=en:Germany LOCATION;LANGUAGE=en:Germany
LOCATION;LANGUAGE=no:Tyskland LOCATION;LANGUAGE=no:Tyskland
3.2.11. Group or List Membership 3.2.11. Group or List Membership
Parameter Name: MEMBER Parameter Name: MEMBER
Purpose: To specify the group or list membership of the calendar Purpose: To specify the group or list membership of the calendar
user specified by the property. user specified by the property.
Format Definition: This property parameter is defined by the Format Definition: This property parameter is defined by the
following notation: following notation:
memberparam = "MEMBER" "=" DQUOTE cal-address DQUOTE memberparam = "MEMBER" "=" DQUOTE cal-address DQUOTE
*("," DQUOTE cal-address DQUOTE) *("," DQUOTE cal-address DQUOTE)
RFC 5545 iCalendar September 2009
Description: This parameter can be specified on properties with a Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. The parameter identifies the groups or CAL-ADDRESS value type. The parameter identifies the groups or
list membership for the calendar user specified by the property. list membership for the calendar user specified by the property.
The parameter value is either a single calendar address in a The parameter value is either a single calendar address in a
quoted-string or a COMMA character (US-ASCII decimal 44) separated quoted-string or a COMMA-separated list of calendar addresses,
list of calendar addresses, each in a quoted-string. The each in a quoted-string. The individual calendar address
individual calendar address parameter values MUST each be parameter values MUST each be specified in a quoted-string.
specified in a quoted-string.
Example: Example:
ATTENDEE;MEMBER="mailto:ietf-calsch@example.org":mailto: ATTENDEE;MEMBER="mailto:ietf-calsch@example.org":mailto:
jsmith@example.com jsmith@example.com
ATTENDEE;MEMBER="mailto:projectA@example.com","mailto:pr ATTENDEE;MEMBER="mailto:projectA@example.com","mailto:pr
ojectB@example.com":mailto:janedoe@example.com ojectB@example.com":mailto:janedoe@example.com
3.2.12. Participation Status 3.2.12. Participation Status
Parameter Name: PARTSTAT Parameter Name: PARTSTAT
Purpose: To specify the participation status for the calendar user Purpose: To specify the participation status for the calendar user
specified by the property. specified by the property.
Format Definition: This property parameter is defined by the Format Definition: This property parameter is defined by the
following notation: following notation:
partstatparam = "PARTSTAT" "=" partstatparam = "PARTSTAT" "="
(partstat-event (partstat-event
/ partstat-todo / partstat-todo
/ partstat-jour) / partstat-jour)
partstat-event = ("NEEDS-ACTION" ; Event needs action partstat-event = ("NEEDS-ACTION" ; Event needs action
/ "ACCEPTED" ; Event accepted / "ACCEPTED" ; Event accepted
/ "DECLINED" ; Event declined / "DECLINED" ; Event declined
/ "TENTATIVE" ; Event tentatively / "TENTATIVE" ; Event tentatively
; accepted ; accepted
/ "DELEGATED" ; Event delegated / "DELEGATED" ; Event delegated
/ x-name ; Experimental status / x-name ; Experimental status
/ iana-token) ; Other IANA registered / iana-token) ; Other IANA-registered
; status ; status
; These are the participation statuses for a "VEVENT". ; These are the participation statuses for a "VEVENT".
; Default is NEEDS-ACTION. ; Default is NEEDS-ACTION.
partstat-todo = ("NEEDS-ACTION" ; To-do needs action partstat-todo = ("NEEDS-ACTION" ; To-do needs action
/ "ACCEPTED" ; To-do accepted / "ACCEPTED" ; To-do accepted
/ "DECLINED" ; To-do declined / "DECLINED" ; To-do declined
/ "TENTATIVE" ; To-do tentatively / "TENTATIVE" ; To-do tentatively
; accepted ; accepted
/ "DELEGATED" ; To-do delegated
/ "COMPLETED" ; To-do completed.
; COMPLETED property has
; date/time completed.
/ "IN-PROCESS" ; To-do in process of
; being completed
/ x-name ; Experimental status
/ iana-token) ; Other IANA registered
; status
; These are the participation statuses for a "VTODO".
; Default is NEEDS-ACTION.
partstat-jour = ("NEEDS-ACTION" ; Journal needs action RFC 5545 iCalendar September 2009
/ "ACCEPTED" ; Journal accepted
/ "DECLINED" ; Journal declined / "DELEGATED" ; To-do delegated
/ x-name ; Experimental status / "COMPLETED" ; To-do completed
/ iana-token) ; Other IANA registered ; COMPLETED property has
; status ; DATE-TIME completed
; These are the participation statuses for a "VJOURNAL". / "IN-PROCESS" ; To-do in process of
; Default is NEEDS-ACTION. ; being completed
/ x-name ; Experimental status
/ iana-token) ; Other IANA-registered
; status
; These are the participation statuses for a "VTODO".
; Default is NEEDS-ACTION.
partstat-jour = ("NEEDS-ACTION" ; Journal needs action
/ "ACCEPTED" ; Journal accepted
/ "DECLINED" ; Journal declined
/ x-name ; Experimental status
/ iana-token) ; Other IANA-registered
; status
; These are the participation statuses for a "VJOURNAL".
; Default is NEEDS-ACTION.
Description: This parameter can be specified on properties with a Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. The parameter identifies the CAL-ADDRESS value type. The parameter identifies the
participation status for the calendar user specified by the participation status for the calendar user specified by the
property value. The parameter values differ depending on whether property value. The parameter values differ depending on whether
they are associated with a group scheduled "VEVENT", "VTODO" or they are associated with a group-scheduled "VEVENT", "VTODO", or
"VJOURNAL". The values MUST match one of the values allowed for "VJOURNAL". The values MUST match one of the values allowed for
the given calendar component. If not specified on a property that the given calendar component. If not specified on a property that
allows this parameter, the default value is NEEDS-ACTION. allows this parameter, the default value is NEEDS-ACTION.
Applications MUST treat x-name and iana-token value they don't Applications MUST treat x-name and iana-token values they don't
recognized the same way as they would the NEEDS-ACTION value. recognize the same way as they would the NEEDS-ACTION value.
Example: Example:
ATTENDEE;PARTSTAT=DECLINED:mailto:jsmith@example.com ATTENDEE;PARTSTAT=DECLINED:mailto:jsmith@example.com
3.2.13. Recurrence Identifier Range 3.2.13. Recurrence Identifier Range
Parameter Name: RANGE Parameter Name: RANGE
Purpose: To specify the effective range of recurrence instances from Purpose: To specify the effective range of recurrence instances from
the instance specified by the recurrence identifier specified by the instance specified by the recurrence identifier specified by
the property. the property.
Format Definition: This property parameter is defined by the Format Definition: This property parameter is defined by the
following notation: following notation:
rangeparam = "RANGE" "=" "THISANDFUTURE" RFC 5545 iCalendar September 2009
; To specify the instance specified by the recurrence identifier
; and all subsequent recurrence instances rangeparam = "RANGE" "=" "THISANDFUTURE"
; To specify the instance specified by the recurrence identifier
; and all subsequent recurrence instances.
Description: This parameter can be specified on a property that Description: This parameter can be specified on a property that
specifies a recurrence identifier. The parameter specifies the specifies a recurrence identifier. The parameter specifies the
effective range of recurrence instances that is specified by the effective range of recurrence instances that is specified by the
property. The effective range is from the recurrence identifier property. The effective range is from the recurrence identifier
specified by the property. If this parameter is not specified on specified by the property. If this parameter is not specified on
an allowed property, then the default range is the single instance an allowed property, then the default range is the single instance
specified by the recurrence identifier value of the property. The specified by the recurrence identifier value of the property. The
parameter value can only be "THISANDFUTURE" to indicate a range parameter value can only be "THISANDFUTURE" to indicate a range
defined by the recurrence identifier and all subsequent instances. defined by the recurrence identifier and all subsequent instances.
The value "THISANDPRIOR" is deprecated by this revision of The value "THISANDPRIOR" is deprecated by this revision of
iCalendar and MUST NOT be generated by applications. iCalendar and MUST NOT be generated by applications.
Example: Example:
RECURRENCE-ID;RANGE=THISANDFUTURE:19980401T133000Z RECURRENCE-ID;RANGE=THISANDFUTURE:19980401T133000Z
3.2.14. Alarm Trigger Relationship 3.2.14. Alarm Trigger Relationship
Parameter Name: RELATED Parameter Name: RELATED
Purpose: To specify the relationship of the alarm trigger with Purpose: To specify the relationship of the alarm trigger with
respect to the start or end of the calendar component. respect to the start or end of the calendar component.
Format Definition: This property parameter is defined by the Format Definition: This property parameter is defined by the
following notation: following notation:
trigrelparam = "RELATED" "=" trigrelparam = "RELATED" "="
("START" ; Trigger off of start ("START" ; Trigger off of start
/ "END") ; Trigger off of end / "END") ; Trigger off of end
Description: This parameter can be specified on properties that Description: This parameter can be specified on properties that
specify an alarm trigger with a "DURATION" value type. The specify an alarm trigger with a "DURATION" value type. The
parameter specifies whether the alarm will trigger relative to the parameter specifies whether the alarm will trigger relative to the
start or end of the calendar component. The parameter value START start or end of the calendar component. The parameter value START
will set the alarm to trigger off the start of the calendar will set the alarm to trigger off the start of the calendar
component; the parameter value END will set the alarm to trigger component; the parameter value END will set the alarm to trigger
off the end of the calendar component. If the parameter is not off the end of the calendar component. If the parameter is not
specified on an allowable property, then the default is START. specified on an allowable property, then the default is START.
Example: Example:
TRIGGER;RELATED=END:PT5M TRIGGER;RELATED=END:PT5M
RFC 5545 iCalendar September 2009
3.2.15. Relationship Type 3.2.15. Relationship Type
Parameter Name: RELTYPE Parameter Name: RELTYPE
Purpose: To specify the type of hierarchical relationship associated Purpose: To specify the type of hierarchical relationship associated
with the calendar component specified by the property. with the calendar component specified by the property.
Format Definition: This property parameter is defined by the Format Definition: This property parameter is defined by the
following notation: following notation:
reltypeparam = "RELTYPE" "=" reltypeparam = "RELTYPE" "="
("PARENT" ; Parent relationship. Default. ("PARENT" ; Parent relationship - Default
/ "CHILD" ; Child relationship / "CHILD" ; Child relationship
/ "SIBLING" ; Sibling relationship / "SIBLING" ; Sibling relationship
/ iana-token ; Some other IANA registered / iana-token ; Some other IANA-registered
; iCalendar relationship type ; iCalendar relationship type
/ x-name) ; A non-standard, experimental / x-name) ; A non-standard, experimental
; relationship type ; relationship type
Description: This parameter can be specified on a property that Description: This parameter can be specified on a property that
references another related calendar. The parameter specifies the references another related calendar. The parameter specifies the
hierarchical relationship type of the calendar component hierarchical relationship type of the calendar component
referenced by the property. The parameter value can be PARENT, to referenced by the property. The parameter value can be PARENT, to
indicate that the referenced calendar component is a superior of indicate that the referenced calendar component is a superior of
calendar component; CHILD to indicate that the referenced calendar calendar component; CHILD to indicate that the referenced calendar
component is a subordinate of the calendar component; SIBLING to component is a subordinate of the calendar component; or SIBLING
indicate that the referenced calendar component is a peer of the to indicate that the referenced calendar component is a peer of
calendar component. If this parameter is not specified on an the calendar component. If this parameter is not specified on an
allowable property, the default relationship type is PARENT. allowable property, the default relationship type is PARENT.
Applications MUST treat x-name and iana-token value they don't Applications MUST treat x-name and iana-token values they don't
recognized the same way as they would the PARENT value. recognize the same way as they would the PARENT value.
Example: Example:
RELATED-TO;RELTYPE=SIBLING:19960401-080045-4000F192713@ RELATED-TO;RELTYPE=SIBLING:19960401-080045-4000F192713@
example.com example.com
3.2.16. Participation Role 3.2.16. Participation Role
Parameter Name: ROLE Parameter Name: ROLE
Purpose: To specify the participation role for the calendar user Purpose: To specify the participation role for the calendar user
specified by the property. specified by the property.
Format Definition: This property parameter is defined by the Format Definition: This property parameter is defined by the
following notation: following notation:
roleparam = "ROLE" "=" RFC 5545 iCalendar September 2009
("CHAIR" ; Indicates chair of the
; calendar entity roleparam = "ROLE" "="
/ "REQ-PARTICIPANT" ; Indicates a participant whose ("CHAIR" ; Indicates chair of the
; participation is required ; calendar entity
/ "OPT-PARTICIPANT" ; Indicates a participant whose / "REQ-PARTICIPANT" ; Indicates a participant whose
; participation is optional ; participation is required
/ "NON-PARTICIPANT" ; Indicates a participant who / "OPT-PARTICIPANT" ; Indicates a participant whose
; is copied for information ; participation is optional
; purposes only / "NON-PARTICIPANT" ; Indicates a participant who
/ x-name ; Experimental role ; is copied for information
/ iana-token) ; Other IANA role ; purposes only
; Default is REQ-PARTICIPANT / x-name ; Experimental role
/ iana-token) ; Other IANA role
; Default is REQ-PARTICIPANT
Description: This parameter can be specified on properties with a Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. The parameter specifies the participation CAL-ADDRESS value type. The parameter specifies the participation
role for the calendar user specified by the property in the group role for the calendar user specified by the property in the group
schedule calendar component. If not specified on a property that schedule calendar component. If not specified on a property that
allows this parameter, the default value is REQ-PARTICIPANT. allows this parameter, the default value is REQ-PARTICIPANT.
Applications MUST treat x-name and iana-token value they don't Applications MUST treat x-name and iana-token values they don't
recognized the same way as they would the REQ-PARTICIPANT value. recognize the same way as they would the REQ-PARTICIPANT value.
Example: Example:
ATTENDEE;ROLE=CHAIR:mailto:mrbig@example.com ATTENDEE;ROLE=CHAIR:mailto:mrbig@example.com
3.2.17. RSVP Expectation 3.2.17. RSVP Expectation
Parameter Name: RSVP Parameter Name: RSVP
Purpose: To specify whether there is an expectation of a favor of a Purpose: To specify whether there is an expectation of a favor of a
reply from the calendar user specified by the property value. reply from the calendar user specified by the property value.
Format Definition: This property parameter is defined by the Format Definition: This property parameter is defined by the
following notation: following notation:
rsvpparam = "RSVP" "=" ("TRUE" / "FALSE") rsvpparam = "RSVP" "=" ("TRUE" / "FALSE")
; Default is FALSE ; Default is FALSE
Description: This parameter can be specified on properties with a Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. The parameter identifies the expectation CAL-ADDRESS value type. The parameter identifies the expectation
of a reply from the calendar user specified by the property value. of a reply from the calendar user specified by the property value.
This parameter is used by the "Organizer" to request a This parameter is used by the "Organizer" to request a
participation status reply from an "Attendee" of a group scheduled participation status reply from an "Attendee" of a group-scheduled
event or to-do. If not specified on a property that allows this event or to-do. If not specified on a property that allows this
parameter, the default value is FALSE. parameter, the default value is FALSE.
RFC 5545 iCalendar September 2009
Example: Example:
ATTENDEE;RSVP=TRUE:mailto:jsmith@example.com ATTENDEE;RSVP=TRUE:mailto:jsmith@example.com
3.2.18. Sent By 3.2.18. Sent By
Parameter Name: SENT-BY Parameter Name: SENT-BY
Purpose: To specify the calendar user that is acting on behalf of Purpose: To specify the calendar user that is acting on behalf of
the calendar user specified by the property. the calendar user specified by the property.
Format Definition: This property parameter is defined by the Format Definition: This property parameter is defined by the
following notation: following notation:
sentbyparam = "SENT-BY" "=" DQUOTE cal-address DQUOTE sentbyparam = "SENT-BY" "=" DQUOTE cal-address DQUOTE
Description: This parameter can be specified on properties with a Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. The parameter specifies the calendar user CAL-ADDRESS value type. The parameter specifies the calendar user
that is acting on behalf of the calendar user specified by the that is acting on behalf of the calendar user specified by the
property. The parameter value MUST be a mailto URI as defined in property. The parameter value MUST be a mailto URI as defined in
[RFC2368]. The individual calendar address parameter values MUST [RFC2368]. The individual calendar address parameter values MUST
each be specified in a quoted-string. each be specified in a quoted-string.
Example: Example:
ORGANIZER;SENT-BY="mailto:sray@example.com":mailto: ORGANIZER;SENT-BY="mailto:sray@example.com":mailto:
jsmith@example.com jsmith@example.com
3.2.19. Time Zone Identifier 3.2.19. Time Zone Identifier
Parameter Name: TZID Parameter Name: TZID
Purpose: To specify the identifier for the time zone definition for Purpose: To specify the identifier for the time zone definition for
a time component in the property value. a time component in the property value.
Format Definition: This property parameter is defined by the Format Definition: This property parameter is defined by the
following notation: following notation:
tzidparam = "TZID" "=" [tzidprefix] paramtext tzidparam = "TZID" "=" [tzidprefix] paramtext
tzidprefix = "/"
tzidprefix = "/"
Description: This parameter MUST be specified on the "DTSTART", Description: This parameter MUST be specified on the "DTSTART",
"DTEND", "DUE", "EXDATE" and "RDATE" properties when either a "DTEND", "DUE", "EXDATE", and "RDATE" properties when either a
DATE-TIME or TIME value type is specified and when the value is DATE-TIME or TIME value type is specified and when the value is
not either a UTC or a "floating" time. Refer to the DATE-TIME or neither a UTC or a "floating" time. Refer to the DATE-TIME or
TIME value type definition for a description of UTC and "floating TIME value type definition for a description of UTC and "floating
time" formats. This property parameter specifies a text value time" formats. This property parameter specifies a text value
which uniquely identifies the "VTIMEZONE" calendar component to be
RFC 5545 iCalendar September 2009
that uniquely identifies the "VTIMEZONE" calendar component to be
used when evaluating the time portion of the property. The value used when evaluating the time portion of the property. The value
of the "TZID" property parameter will be equal to the value of the of the "TZID" property parameter will be equal to the value of the
"TZID" property for the matching time zone definition. An "TZID" property for the matching time zone definition. An
individual "VTIMEZONE" calendar component MUST be specified for individual "VTIMEZONE" calendar component MUST be specified for
each unique "TZID" parameter value specified in the iCalendar each unique "TZID" parameter value specified in the iCalendar
object. object.
The parameter MUST be specified on properties with a DATE-TIME The parameter MUST be specified on properties with a DATE-TIME
value if the DATE-TIME is not either a UTC or a "floating" time. value if the DATE-TIME is not either a UTC or a "floating" time.
Failure to include and follow VTIMEZONE definitions in iCalendar
objects may lead to inconsistent understanding of the local time
at any given location.
The presence of the SOLIDUS character (US-ASCII decimal 47) as a The presence of the SOLIDUS character as a prefix, indicates that
prefix, indicates that this "TZID" represents a unique ID in a this "TZID" represents a unique ID in a globally defined time zone
globally defined time zone registry (when such registry is registry (when such registry is defined).
defined).
Note: This document does not define a naming convention for Note: This document does not define a naming convention for
time zone identifiers. Implementers may want to use the naming time zone identifiers. Implementers may want to use the naming
conventions defined in existing time zone specifications such conventions defined in existing time zone specifications such
as the public-domain TZ database [TZDB]. The specification of as the public-domain TZ database [TZDB]. The specification of
globally unique time zone identifiers is not addressed by this globally unique time zone identifiers is not addressed by this
document and is left for future study. document and is left for future study.
The following are examples of this property parameter: The following are examples of this property parameter:
DTSTART;TZID=America/New_York:19980119T020000 DTSTART;TZID=America/New_York:19980119T020000
DTEND;TZID=America/New_York:19980119T030000 DTEND;TZID=America/New_York:19980119T030000
The "TZID" property parameter MUST NOT be applied to DATE The "TZID" property parameter MUST NOT be applied to DATE
properties, and DATE-TIME or TIME properties whose time values are properties and DATE-TIME or TIME properties whose time values are
specified in UTC. specified in UTC.
The use of local time in a DATE-TIME or TIME value without the The use of local time in a DATE-TIME or TIME value without the
"TZID" property parameter is to be interpreted as floating time, "TZID" property parameter is to be interpreted as floating time,
regardless of the existence of "VTIMEZONE" calendar components in regardless of the existence of "VTIMEZONE" calendar components in
the iCalendar object. the iCalendar object.
For more information see the sections on the value types DATE-TIME For more information, see the sections on the value types DATE-
and TIME. TIME and TIME.
RFC 5545 iCalendar September 2009
3.2.20. Value Data Types 3.2.20. Value Data Types
Parameter Name: VALUE Parameter Name: VALUE
Purpose: To explicitly specify the value type format for a property Purpose: To explicitly specify the value type format for a property
value. value.
Format Definition: This property parameter is defined by the Format Definition: This property parameter is defined by the
following notation: following notation:
valuetypeparam = "VALUE" "=" valuetype valuetypeparam = "VALUE" "=" valuetype
valuetype = ("BINARY" valuetype = ("BINARY"
/ "BOOLEAN" / "BOOLEAN"
/ "CAL-ADDRESS" / "CAL-ADDRESS"
/ "DATE" / "DATE"
/ "DATE-TIME" / "DATE-TIME"
/ "DURATION" / "DURATION"
/ "FLOAT" / "FLOAT"
/ "INTEGER" / "INTEGER"
/ "PERIOD" / "PERIOD"
/ "RECUR" / "RECUR"
/ "TEXT" / "TEXT"
/ "TIME" / "TIME"
/ "URI" / "URI"
/ "UTC-OFFSET" / "UTC-OFFSET"
/ x-name / x-name
; Some experimental iCalendar value type. ; Some experimental iCalendar value type.
/ iana-token) / iana-token)
; Some other IANA registered iCalendar value type. ; Some other IANA-registered iCalendar value type.
Description: This parameter specifies the value type and format of Description: This parameter specifies the value type and format of
the property value. The property values MUST be of a single value the property value. The property values MUST be of a single value
type. For example, a "RDATE" property cannot have a combination type. For example, a "RDATE" property cannot have a combination
of DATE-TIME and TIME value types. of DATE-TIME and TIME value types.
If the property's value is the default value type, then this If the property's value is the default value type, then this
parameter need not be specified. However, if the property's parameter need not be specified. However, if the property's
default value type is overridden by some other allowable value default value type is overridden by some other allowable value
type, then this parameter MUST be specified. type, then this parameter MUST be specified.
Applications MUST preserve the value data for x-name and iana- Applications MUST preserve the value data for x-name and iana-
token values that they don't recognize without attempting to token values that they don't recognize without attempting to
interpret or parse the value data. interpret or parse the value data.
RFC 5545 iCalendar September 2009
3.3. Property Value Data Types 3.3. Property Value Data Types
The properties in an iCalendar object are strongly typed. The The properties in an iCalendar object are strongly typed. The
definition of each property restricts the value to be one of the definition of each property restricts the value to be one of the
value data types, or simply value types, defined in this section. value data types, or simply value types, defined in this section.
The value type for a property will either be specified implicitly as The value type for a property will either be specified implicitly as
the default value type or will be explicitly specified with the the default value type or will be explicitly specified with the
"VALUE" parameter. If the value type of a property is one of the "VALUE" parameter. If the value type of a property is one of the
alternate valid types, then it MUST be explicitly specified with the alternate valid types, then it MUST be explicitly specified with the
"VALUE" parameter. "VALUE" parameter.
skipping to change at page 32, line 28 skipping to change at page 30, line 30
Value Name: BINARY Value Name: BINARY
Purpose: This value type is used to identify properties that contain Purpose: This value type is used to identify properties that contain
a character encoding of inline binary data. For example, an a character encoding of inline binary data. For example, an
inline attachment of a document might be included in an iCalendar inline attachment of a document might be included in an iCalendar
object. object.
Format Definition: This value type is defined by the following Format Definition: This value type is defined by the following
notation: notation:
binary = *(4b-char) [b-end] binary = *(4b-char) [b-end]
; A "BASE64" encoded character string, as defined by [RFC4648]. ; A "BASE64" encoded character string, as defined by [RFC4648].
b-end = (2b-char "==") / (3b-char "=") b-end = (2b-char "==") / (3b-char "=")
b-char = ALPHA / DIGIT / "+" / "/" b-char = ALPHA / DIGIT / "+" / "/"
Description: Property values with this value type MUST also include Description: Property values with this value type MUST also include
the inline encoding parameter sequence of ";ENCODING=BASE64". the inline encoding parameter sequence of ";ENCODING=BASE64".
That is, all inline binary data MUST first be character encoded That is, all inline binary data MUST first be character encoded
using the "BASE64" encoding method defined in [RFC2045]. No using the "BASE64" encoding method defined in [RFC2045]. No
additional content value encoding (i.e., BACKSLASH character additional content value encoding (i.e., BACKSLASH character
encoding, see Section 3.3.11) is defined for this value type. encoding, see Section 3.3.11) is defined for this value type.
RFC 5545 iCalendar September 2009
Example: The following is an example of a "BASE64" encoded binary Example: The following is an example of a "BASE64" encoded binary
value data. value data:
ATTACH;FMTTYPE=image/vnd.microsoft.icon;ENCODING=BASE64;VALUE ATTACH;FMTTYPE=image/vnd.microsoft.icon;ENCODING=BASE64;VALUE
=BINARY:AAABAAEAEBAQAAEABAAoAQAAFgAAACgAAAAQAAAAIAAAAAEABAAA =BINARY:AAABAAEAEBAQAAEABAAoAQAAFgAAACgAAAAQAAAAIAAAAAEABAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAACAAAAAgIAAAICAgADAwMAA////AAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAACAAAAAgIAAAICAgADAwMAA////AAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAMwAAAAAAABNEMQAAAAAAAkQgAAAAAAJEREQgAA AAAAAAAAAAAAAAAAAAAAAAMwAAAAAAABNEMQAAAAAAAkQgAAAAAAJEREQgAA
ACECQ0QgEgAAQxQzM0E0AABERCRCREQAADRDJEJEQwAAAhA0QwEQAAAAAERE ACECQ0QgEgAAQxQzM0E0AABERCRCREQAADRDJEJEQwAAAhA0QwEQAAAAAERE
AAAAAAAAREQAAAAAAAAkQgAAAAAAAAMgAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAREQAAAAAAAAkQgAAAAAAAAMgAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA
AAAAAAAAAAAA AAAAAAAAAAAA
3.3.2. Boolean 3.3.2. Boolean
Value Name: BOOLEAN Value Name: BOOLEAN
Purpose: This value type is used to identify properties that contain Purpose: This value type is used to identify properties that contain
either a "TRUE" or "FALSE" Boolean value. either a "TRUE" or "FALSE" Boolean value.
Format Definition: This value type is defined by the following Format Definition: This value type is defined by the following
notation: notation:
boolean = "TRUE" / "FALSE" boolean = "TRUE" / "FALSE"
Description: These values are case insensitive text. No additional Description: These values are case-insensitive text. No additional
content value encoding (i.e., BACKSLASH character encoding, see content value encoding (i.e., BACKSLASH character encoding, see
Section 3.3.11) is defined for this value type. Section 3.3.11) is defined for this value type.
Example: The following is an example of a hypothetical property that Example: The following is an example of a hypothetical property that
has a BOOLEAN value type: has a BOOLEAN value type:
TRUE TRUE
3.3.3. Calendar User Address 3.3.3. Calendar User Address
Value Name: CAL-ADDRESS Value Name: CAL-ADDRESS
Purpose: This value type is used to identify properties that contain Purpose: This value type is used to identify properties that contain
a calendar user address. a calendar user address.
Format Definition: This value type is defined by the following Format Definition: This value type is defined by the following
notation: notation:
cal-address = uri cal-address = uri
Description: The value is a URI as defined by [RFC3986] or any other Description: The value is a URI as defined by [RFC3986] or any other
IANA registered form for a URI. When used to address an Internet IANA-registered form for a URI. When used to address an Internet
RFC 5545 iCalendar September 2009
email transport address for a calendar user, the value MUST be a email transport address for a calendar user, the value MUST be a
mailto URI, as defined by [RFC2368]. No additional content value mailto URI, as defined by [RFC2368]. No additional content value
encoding (i.e., BACKSLASH character encoding, see Section 3.3.11) encoding (i.e., BACKSLASH character encoding, see Section 3.3.11)
is defined for this value type. is defined for this value type.
Example: Example:
mailto:jane_doe@example.com mailto:jane_doe@example.com
3.3.4. Date 3.3.4. Date
Value Name: DATE Value Name: DATE
Purpose: This value type is used to identify values that contain a Purpose: This value type is used to identify values that contain a
calendar date. calendar date.
Format Definition: This value type is defined by the following Format Definition: This value type is defined by the following
notation: notation:
date = date-value date = date-value
date-value = date-fullyear date-month date-mday date-value = date-fullyear date-month date-mday
date-fullyear = 4DIGIT date-fullyear = 4DIGIT
date-month = 2DIGIT ;01-12 date-month = 2DIGIT ;01-12
date-mday = 2DIGIT ;01-28, 01-29, 01-30, 01-31 date-mday = 2DIGIT ;01-28, 01-29, 01-30, 01-31
;based on month/year ;based on month/year
Description: If the property permits, multiple "date" values are Description: If the property permits, multiple "date" values are
specified as a COMMA character (US-ASCII decimal 44) separated specified as a COMMA-separated list of values. The format for the
list of values. The format for the value type is based on the value type is based on the [ISO.8601.2004] complete
[ISO.8601.2004] complete representation, basic format for a representation, basic format for a calendar date. The textual
calendar date. The textual format specifies a four-digit year, format specifies a four-digit year, two-digit month, and two-digit
two-digit month, and two-digit day of the month. There are no day of the month. There are no separator characters between the
separator characters between the year, month and day component year, month, and day component text.
text.
No additional content value encoding (i.e., BACKSLASH character No additional content value encoding (i.e., BACKSLASH character
encoding, see Section 3.3.11) is defined for this value type. encoding, see Section 3.3.11) is defined for this value type.
Example: The following represents July 14, 1997: Example: The following represents July 14, 1997:
19970714 19970714
3.3.5. Date-Time 3.3.5. Date-Time
Value Name: DATE-TIME Value Name: DATE-TIME
Purpose: This value type is used to identify values that specify a Purpose: This value type is used to identify values that specify a
precise calendar date and time of day. precise calendar date and time of day.
RFC 5545 iCalendar September 2009
Format Definition: This value type is defined by the following Format Definition: This value type is defined by the following
notation: notation:
date-time = date "T" time ;As specified in the date and time date-time = date "T" time ;As specified in the DATE and TIME
;value definitions ;value definitions
Description: If the property permits, multiple "date-time" values Description: If the property permits, multiple "DATE-TIME" values
are specified as a COMMA character (US-ASCII decimal 44) separated are specified as a COMMA-separated list of values. No additional
list of values. No additional content value encoding (i.e., content value encoding (i.e., BACKSLASH character encoding, see
BACKSLASH character encoding, see Section 3.3.11) is defined for Section 3.3.11) is defined for this value type.
this value type.
The "DATE-TIME" value type is used to identify values that contain The "DATE-TIME" value type is used to identify values that contain
a precise calendar date and time of day. The format is based on a precise calendar date and time of day. The format is based on
the [ISO.8601.2004] complete representation, basic format for a the [ISO.8601.2004] complete representation, basic format for a
calendar date and time of day. The text format is a concatenation calendar date and time of day. The text format is a concatenation
of the "date", followed by the LATIN CAPITAL LETTER T character of the "date", followed by the LATIN CAPITAL LETTER T character,
(US-ASCII decimal 84) time designator, followed by the "time" the time designator, followed by the "time" format.
format.
The "DATE-TIME" value type expresses time values in three forms: The "DATE-TIME" value type expresses time values in three forms:
The form of date and time with UTC offset MUST NOT be used. For The form of date and time with UTC offset MUST NOT be used. For
example, the following is not valid for a date-time value: example, the following is not valid for a DATE-TIME value:
19980119T230000-0800 ;Invalid time format 19980119T230000-0800 ;Invalid time format
FORM #1: DATE WITH LOCAL TIME FORM #1: DATE WITH LOCAL TIME
The date with local time form is simply a DATE-TIME value that The date with local time form is simply a DATE-TIME value that
does not contain the UTC designator nor does it reference a time does not contain the UTC designator nor does it reference a time
zone. For example, the following represents January 18, 1998, at zone. For example, the following represents January 18, 1998, at
11 PM: 11 PM:
19980118T230000 19980118T230000
DATE-TIME values of this type are said to be "floating" and are DATE-TIME values of this type are said to be "floating" and are
not bound to any time zone in particular. They are used to not bound to any time zone in particular. They are used to
represent the same hour, minute, and second value regardless of represent the same hour, minute, and second value regardless of
which time zone is currently being observed. For example, an which time zone is currently being observed. For example, an
event can be defined that indicates that an individual will be event can be defined that indicates that an individual will be
busy from 11:00 AM to 1:00 PM every day, no matter which time zone busy from 11:00 AM to 1:00 PM every day, no matter which time zone
the person is in. In these cases, a local time can be specified. the person is in. In these cases, a local time can be specified.
The recipient of an iCalendar object with a property value The recipient of an iCalendar object with a property value
consisting of a local time, without any relative time zone consisting of a local time, without any relative time zone
information, SHOULD interpret the value as being fixed to whatever information, SHOULD interpret the value as being fixed to whatever
time zone the "ATTENDEE" is in at any given moment. This means time zone the "ATTENDEE" is in at any given moment. This means
that two "Attendees", in different time zones, receiving the same that two "Attendees", in different time zones, receiving the same
event definition as a floating time, may be participating in the event definition as a floating time, may be participating in the
RFC 5545 iCalendar September 2009
event at different actual times. Floating time SHOULD only be event at different actual times. Floating time SHOULD only be
used where that is the reasonable behavior. used where that is the reasonable behavior.
In most cases, a fixed time is desired. To properly communicate a In most cases, a fixed time is desired. To properly communicate a
fixed time in a property value, either UTC time or local time with fixed time in a property value, either UTC time or local time with
time zone reference MUST be specified. time zone reference MUST be specified.
The use of local time in a DATE-TIME value without the "TZID" The use of local time in a DATE-TIME value without the "TZID"
property parameter is to be interpreted as floating time, property parameter is to be interpreted as floating time,
regardless of the existence of "VTIMEZONE" calendar components in regardless of the existence of "VTIMEZONE" calendar components in
the iCalendar object. the iCalendar object.
FORM #2: DATE WITH UTC TIME FORM #2: DATE WITH UTC TIME
The date with UTC time, or absolute time, is identified by a LATIN The date with UTC time, or absolute time, is identified by a LATIN
CAPITAL LETTER Z suffix character (US-ASCII decimal 90), the UTC CAPITAL LETTER Z suffix character, the UTC designator, appended to
designator, appended to the time value. For example, the the time value. For example, the following represents January 19,
following represents January 19, 1998, at 0700 UTC: 1998, at 0700 UTC:
19980119T070000Z 19980119T070000Z
The "TZID" property parameter MUST NOT be applied to DATE-TIME The "TZID" property parameter MUST NOT be applied to DATE-TIME
properties whose time values are specified in UTC. properties whose time values are specified in UTC.
FORM #3: DATE WITH LOCAL TIME AND TIME ZONE REFERENCE FORM #3: DATE WITH LOCAL TIME AND TIME ZONE REFERENCE
The date and local time with reference to time zone information is The date and local time with reference to time zone information is
identified by the use the "TZID" property parameter to reference identified by the use the "TZID" property parameter to reference
the appropriate time zone definition. "TZID" is discussed in the appropriate time zone definition. "TZID" is discussed in
detail in Section 3.2.19. For example, the following represents detail in Section 3.2.19. For example, the following represents
2:00 A.M. in New York on Janurary 19, 1998: 2:00 A.M. in New York on January 19, 1998:
TZID=America/New_York:19980119T020000 TZID=America/New_York:19980119T020000
If, based on the definition of the referenced time zone, the local If, based on the definition of the referenced time zone, the local
time described occurs more than once (when changing from daylight time described occurs more than once (when changing from daylight
to standard time), the DATE-TIME value refers to the first to standard time), the DATE-TIME value refers to the first
occurence of the referenced time. Thus, TZID=America/ occurrence of the referenced time. Thus, TZID=America/
New_York:20071104T013000 indicates November 4, 2007 at 1:30 A.M. New_York:20071104T013000 indicates November 4, 2007 at 1:30 A.M.
EDT (UTC-04:00). If the local time described does not occur (when EDT (UTC-04:00). If the local time described does not occur (when
changing from standard to daylight time), the DATE-TIME value is changing from standard to daylight time), the DATE-TIME value is
interpreted using the UTC offset before the gap in local times. interpreted using the UTC offset before the gap in local times.
Thus, TZID=America/New_York:20070311T023000 indicates March 11, Thus, TZID=America/New_York:20070311T023000 indicates March 11,
2007 at 3:30 A.M. EDT (UTC-04:00), one hour after 1:30 A.M. EST 2007 at 3:30 A.M. EDT (UTC-04:00), one hour after 1:30 A.M. EST
(UTC-05:00). (UTC-05:00).
RFC 5545 iCalendar September 2009
A time value MUST only specify the second 60 when specifying a A time value MUST only specify the second 60 when specifying a
positive leap second. For example: positive leap second. For example:
19970630T235960Z 19970630T235960Z
Implementations which do not support leap seconds SHOULD interpret Implementations that do not support leap seconds SHOULD interpret
the second 60 as equivalent to the second 59. the second 60 as equivalent to the second 59.
Example: The following represents July 14, 1997, at 1:30 PM in New Example: The following represents July 14, 1997, at 1:30 PM in New
York City in each of the three time formats, using the "DTSTART" York City in each of the three time formats, using the "DTSTART"
property. property.
DTSTART:19970714T133000 ; Local time DTSTART:19970714T133000 ; Local time
DTSTART:19970714T173000Z ; UTC time DTSTART:19970714T173000Z ; UTC time
DTSTART;TZID=America/New_York:19970714T133000 DTSTART;TZID=America/New_York:19970714T133000
; Local time and time ; Local time and time
; zone reference ; zone reference
3.3.6. Duration 3.3.6. Duration
Value Name: DURATION Value Name: DURATION
Purpose: This value type is used to identify properties that contain Purpose: This value type is used to identify properties that contain
a duration of time. a duration of time.
Format Definition: This value type is defined by the following Format Definition: This value type is defined by the following
notation: notation:
dur-value = (["+"] / "-") "P" (dur-date / dur-time / dur-week) dur-value = (["+"] / "-") "P" (dur-date / dur-time / dur-week)
dur-date = dur-day [dur-time] dur-date = dur-day [dur-time]
dur-time = "T" (dur-hour / dur-minute / dur-second) dur-time = "T" (dur-hour / dur-minute / dur-second)
dur-week = 1*DIGIT "W" dur-week = 1*DIGIT "W"
dur-hour = 1*DIGIT "H" [dur-minute] dur-hour = 1*DIGIT "H" [dur-minute]
dur-minute = 1*DIGIT "M" [dur-second] dur-minute = 1*DIGIT "M" [dur-second]
dur-second = 1*DIGIT "S" dur-second = 1*DIGIT "S"
dur-day = 1*DIGIT "D" dur-day = 1*DIGIT "D"
Description: If the property permits, multiple "duration" values are Description: If the property permits, multiple "duration" values are
specified by a COMMA character (US-ASCII decimal 44) separated specified by a COMMA-separated list of values. The format is
list of values. The format is based on the [ISO.8601.2004] based on the [ISO.8601.2004] complete representation basic format
complete representation basic format with designators for the with designators for the duration of time. The format can
duration of time. The format can represent nominal durations represent nominal durations (weeks and days) and accurate
(weeks and days) and accurate durations (hours, minutes, and durations (hours, minutes, and seconds). Note that unlike
seconds). Note that unlike [ISO.8601.2004] this value type [ISO.8601.2004], this value type doesn't support the "Y" and "M"
doesn't support the "Y" and "M" designators to specify durations designators to specify durations in terms of years and months.
in terms of years and months.
RFC 5545 iCalendar September 2009
The duration of a week or a day depends on its position in the The duration of a week or a day depends on its position in the
calendar. In the case of discontinuities in the time scale, such calendar. In the case of discontinuities in the time scale, such
as the change from standard time to daylight time and back, the as the change from standard time to daylight time and back, the
computation of the exact duration requires the substraction or computation of the exact duration requires the subtraction or
addition of the change of duration of the discontinuity. Leap addition of the change of duration of the discontinuity. Leap
seconds MUST NOT be considered when computing an exact duration. seconds MUST NOT be considered when computing an exact duration.
When computing an exact duration, the greatest order time When computing an exact duration, the greatest order time
components MUST be added first, that is, the number of days MUST components MUST be added first, that is, the number of days MUST
be added first, followed by the number of hours, number of be added first, followed by the number of hours, number of
minutes, and number of seconds. minutes, and number of seconds.
Negative durations are typically used to schedule an alarm to Negative durations are typically used to schedule an alarm to
trigger before an associated time (see Section 3.8.6.3). trigger before an associated time (see Section 3.8.6.3).
No additional content value encoding (i.e., BACKSLASH character No additional content value encoding (i.e., BACKSLASH character
encoding, see Section 3.3.11) are defined for this value type. encoding, see Section 3.3.11) are defined for this value type.
Example: A duration of 15 days, 5 hours and 20 seconds would be: Example: A duration of 15 days, 5 hours, and 20 seconds would be:
P15DT5H0M20S P15DT5H0M20S
A duration of 7 weeks would be: A duration of 7 weeks would be:
P7W P7W
3.3.7. Float 3.3.7. Float
Value Name: FLOAT Value Name: FLOAT
Purpose: This value type is used to identify properties that contain Purpose: This value type is used to identify properties that contain
a real number value. a real-number value.
Format Definition: This value type is defined by the following Format Definition: This value type is defined by the following
notation: notation:
float = (["+"] / "-") 1*DIGIT ["." 1*DIGIT] float = (["+"] / "-") 1*DIGIT ["." 1*DIGIT]
Description: If the property permits, multiple "float" values are Description: If the property permits, multiple "float" values are
specified by a COMMA character (US-ASCII decimal 44) separated specified by a COMMA-separated list of values.
list of values.
No additional content value encoding (i.e., BACKSLASH character No additional content value encoding (i.e., BACKSLASH character
encoding, see Section 3.3.11) is defined for this value type. encoding, see Section 3.3.11) is defined for this value type.
Example: Example:
1000000.0000001 1000000.0000001
1.333 1.333
-3.14 -3.14
RFC 5545 iCalendar September 2009
3.3.8. Integer 3.3.8. Integer
Value Name: INTEGER Value Name: INTEGER
Purpose: This value type is used to identify properties that contain Purpose: This value type is used to identify properties that contain
a signed integer value. a signed integer value.
Format Definition: This value type is defined by the following Format Definition: This value type is defined by the following
notation: notation:
integer = (["+"] / "-") 1*DIGIT integer = (["+"] / "-") 1*DIGIT
Description: If the property permits, multiple "integer" values are Description: If the property permits, multiple "integer" values are
specified by a COMMA character (US-ASCII decimal 44) separated specified by a COMMA-separated list of values. The valid range
list of values. The valid range for "integer" is -2147483648 to for "integer" is -2147483648 to 2147483647. If the sign is not
2147483647. If the sign is not specified, then the value is specified, then the value is assumed to be positive.
assumed to be positive.
No additional content value encoding (i.e., BACKSLASH character No additional content value encoding (i.e., BACKSLASH character
encoding, see Section 3.3.11) is defined for this value type. encoding, see Section 3.3.11) is defined for this value type.
Example: Example:
1234567890 1234567890
-1234567890 -1234567890
+1234567890 +1234567890
432109876 432109876
3.3.9. Period of Time 3.3.9. Period of Time
Value Name: PERIOD Value Name: PERIOD
Purpose: This value type is used to identify values that contain a Purpose: This value type is used to identify values that contain a
precise period of time. precise period of time.
Format Definition: This value type is defined by the following Format Definition: This value type is defined by the following
notation: notation:
period = period-explicit / period-start period = period-explicit / period-start
period-explicit = date-time "/" date-time period-explicit = date-time "/" date-time
; [ISO.8601.2004] complete representation basic format for a ; [ISO.8601.2004] complete representation basic format for a
; period of time consisting of a start and end. The start MUST ; period of time consisting of a start and end. The start MUST
; be before the end. ; be before the end.
period-start = date-time "/" dur-value period-start = date-time "/" dur-value
; [ISO.8601.2004] complete representation basic format for a ; [ISO.8601.2004] complete representation basic format for a
; period of time consisting of a start and positive duration ; period of time consisting of a start and positive duration
; of time. ; of time.
RFC 5545 iCalendar September 2009
Description: If the property permits, multiple "period" values are Description: If the property permits, multiple "period" values are
specified by a COMMA character (US-ASCII decimal 44) separated specified by a COMMA-separated list of values. There are two
list of values. There are two forms of a period of time. First, forms of a period of time. First, a period of time is identified
a period of time is identified by its start and its end. This by its start and its end. This format is based on the
format is based on the [ISO.8601.2004] complete representation, [ISO.8601.2004] complete representation, basic format for "DATE-
basic format for "DATE-TIME" start of the period, followed by a TIME" start of the period, followed by a SOLIDUS character
SOLIDUS character (US-ASCII decimal 47), followed by the "DATE- followed by the "DATE-TIME" of the end of the period. The start
TIME" of the end of the period. The start of the period MUST be of the period MUST be before the end of the period. Second, a
before the end of the period. Second, a period of time can also period of time can also be defined by a start and a positive
be defined by a start and a positive duration of time. The format duration of time. The format is based on the [ISO.8601.2004]
is based on the [ISO.8601.2004] complete representation, basic complete representation, basic format for the "DATE-TIME" start of
format for the "DATE-TIME" start of the period, followed by a the period, followed by a SOLIDUS character, followed by the
SOLIDUS character (US-ASCII decimal 47), followed by the
[ISO.8601.2004] basic format for "DURATION" of the period. [ISO.8601.2004] basic format for "DURATION" of the period.
Example: The period starting at 18:00:00 UTC, on January 1, 1997 and Example: The period starting at 18:00:00 UTC, on January 1, 1997 and
ending at 07:00:00 UTC on January 2, 1997 would be: ending at 07:00:00 UTC on January 2, 1997 would be:
19970101T180000Z/19970102T070000Z 19970101T180000Z/19970102T070000Z
The period start at 18:00:00 on January 1, 1997 and lasting 5 The period start at 18:00:00 on January 1, 1997 and lasting 5
hours and 30 minutes would be: hours and 30 minutes would be:
19970101T180000Z/PT5H30M 19970101T180000Z/PT5H30M
No additional content value encoding (i.e., BACKSLASH character No additional content value encoding (i.e., BACKSLASH character
encoding, see Section 3.3.11) is defined for this value type. encoding, see Section 3.3.11) is defined for this value type.
3.3.10. Recurrence Rule 3.3.10. Recurrence Rule
Value Name: RECUR Value Name: RECUR
Purpose: This value type is used to identify properties that contain Purpose: This value type is used to identify properties that contain
a recurrence rule specification. a recurrence rule specification.
Format Definition: This value type is defined by the following Format Definition: This value type is defined by the following
notation: notation:
recur = recur-rule-part *( ";" recur-rule-part ) recur = recur-rule-part *( ";" recur-rule-part )
; ;
; The rule parts are not ordered in any ; The rule parts are not ordered in any
; particular sequence ; particular sequence.
; ;
; The FREQ rule part is REQUIRED, ; The FREQ rule part is REQUIRED,
; but MUST NOT occur more than once ; but MUST NOT occur more than once.
; ;
; The UNTIL or COUNT rule parts are OPTIONAL, ; The UNTIL or COUNT rule parts are OPTIONAL,
; but they MUST NOT occur in the same 'recur' ; but they MUST NOT occur in the same 'recur'.
; ;
; The other rule parts are OPTIONAL,
; but MUST NOT occur more than once
recur-rule-part = ( "FREQ" "=" freq ) RFC 5545 iCalendar September 2009
/ ( "UNTIL" "=" enddate )
/ ( "COUNT" "=" 1*DIGIT )
/ ( "INTERVAL" "=" 1*DIGIT )
/ ( "BYSECOND" "=" byseclist )
/ ( "BYMINUTE" "=" byminlist )
/ ( "BYHOUR" "=" byhrlist )
/ ( "BYDAY" "=" bywdaylist )
/ ( "BYMONTHDAY" "=" bymodaylist )
/ ( "BYYEARDAY" "=" byyrdaylist )
/ ( "BYWEEKNO" "=" bywknolist )
/ ( "BYMONTH" "=" bymolist )
/ ( "BYSETPOS" "=" bysplist )
/ ( "WKST" "=" weekday )
freq = "SECONDLY" / "MINUTELY" / "HOURLY" / "DAILY" ; The other rule parts are OPTIONAL,
/ "WEEKLY" / "MONTHLY" / "YEARLY" ; but MUST NOT occur more than once.
enddate = date / date-time recur-rule-part = ( "FREQ" "=" freq )
/ ( "UNTIL" "=" enddate )
/ ( "COUNT" "=" 1*DIGIT )
/ ( "INTERVAL" "=" 1*DIGIT )
/ ( "BYSECOND" "=" byseclist )
/ ( "BYMINUTE" "=" byminlist )
/ ( "BYHOUR" "=" byhrlist )
/ ( "BYDAY" "=" bywdaylist )
/ ( "BYMONTHDAY" "=" bymodaylist )
/ ( "BYYEARDAY" "=" byyrdaylist )
/ ( "BYWEEKNO" "=" bywknolist )
/ ( "BYMONTH" "=" bymolist )
/ ( "BYSETPOS" "=" bysplist )
/ ( "WKST" "=" weekday )
byseclist = ( seconds *("," seconds) ) freq = "SECONDLY" / "MINUTELY" / "HOURLY" / "DAILY"
/ "WEEKLY" / "MONTHLY" / "YEARLY"
seconds = 1*2DIGIT ;0 to 60 enddate = date / date-time
byminlist = ( minutes *("," minutes) ) byseclist = ( seconds *("," seconds) )
minutes = 1*2DIGIT ;0 to 59 seconds = 1*2DIGIT ;0 to 60
byhrlist = ( hour *("," hour) ) byminlist = ( minutes *("," minutes) )
hour = 1*2DIGIT ;0 to 23 minutes = 1*2DIGIT ;0 to 59
bywdaylist = ( weekdaynum *("," weekdaynum) ) byhrlist = ( hour *("," hour) )
weekdaynum = [[plus / minus] ordwk] weekday hour = 1*2DIGIT ;0 to 23
plus = "+" bywdaylist = ( weekdaynum *("," weekdaynum) )
minus = "-" weekdaynum = [[plus / minus] ordwk] weekday
ordwk = 1*2DIGIT ;1 to 53 plus = "+"
weekday = "SU" / "MO" / "TU" / "WE" / "TH" / "FR" / "SA"
;Corresponding to SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY,
;FRIDAY, and SATURDAY days of the week.
bymodaylist = ( monthdaynum *("," monthdaynum) ) minus = "-"
monthdaynum = [plus / minus] ordmoday ordwk = 1*2DIGIT ;1 to 53
ordmoday = 1*2DIGIT ;1 to 31 weekday = "SU" / "MO" / "TU" / "WE" / "TH" / "FR" / "SA"
;Corresponding to SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY,
;FRIDAY, and SATURDAY days of the week.
byyrdaylist = ( yeardaynum *("," yeardaynum) ) RFC 5545 iCalendar September 2009
yeardaynum = [plus / minus] ordyrday bymodaylist = ( monthdaynum *("," monthdaynum) )
ordyrday = 1*3DIGIT ;1 to 366 monthdaynum = [plus / minus] ordmoday
bywknolist = ( weeknum *("," weeknum) ) ordmoday = 1*2DIGIT ;1 to 31
weeknum = [plus / minus] ordwk byyrdaylist = ( yeardaynum *("," yeardaynum) )
bymolist = ( monthnum *("," monthnum) ) yeardaynum = [plus / minus] ordyrday
monthnum = 1*2DIGIT ;1 to 12 ordyrday = 1*3DIGIT ;1 to 366
bysplist = ( setposday *("," setposday) ) bywknolist = ( weeknum *("," weeknum) )
setposday = yeardaynum weeknum = [plus / minus] ordwk
bymolist = ( monthnum *("," monthnum) )
monthnum = 1*2DIGIT ;1 to 12
bysplist = ( setposday *("," setposday) )
setposday = yeardaynum
Description: This value type is a structured value consisting of a Description: This value type is a structured value consisting of a
list of one or more recurrence grammar parts. Each rule part is list of one or more recurrence grammar parts. Each rule part is
defined by a NAME=VALUE pair. The rule parts are separated from defined by a NAME=VALUE pair. The rule parts are separated from
each other by the SEMICOLON character (US-ASCII decimal 59). The each other by the SEMICOLON character. The rule parts are not
rule parts are not ordered in any particular sequence. Individual ordered in any particular sequence. Individual rule parts MUST
rule parts MUST only be specified once. Compliant applications only be specified once. Compliant applications MUST accept rule
MUST accept rule parts ordered in any sequence, but to ensure parts ordered in any sequence, but to ensure backward
backward compatibility with applications that pre-date this compatibility with applications that pre-date this revision of
revision of iCalendar the FREQ rule part MUST be the first rule iCalendar the FREQ rule part MUST be the first rule part specified
part specified in a RECUR value. in a RECUR value.
The FREQ rule part identifies the type of recurrence rule. This The FREQ rule part identifies the type of recurrence rule. This
rule part MUST be specified in the recurrence rule. Valid values rule part MUST be specified in the recurrence rule. Valid values
include SECONDLY, to specify repeating events based on an interval include SECONDLY, to specify repeating events based on an interval
of a second or more; MINUTELY, to specify repeating events based of a second or more; MINUTELY, to specify repeating events based
on an interval of a minute or more; HOURLY, to specify repeating on an interval of a minute or more; HOURLY, to specify repeating
events based on an interval of an hour or more; DAILY, to specify events based on an interval of an hour or more; DAILY, to specify
repeating events based on an interval of a day or more; WEEKLY, to repeating events based on an interval of a day or more; WEEKLY, to
specify repeating events based on an interval of a week or more; specify repeating events based on an interval of a week or more;
MONTHLY, to specify repeating events based on an interval of a MONTHLY, to specify repeating events based on an interval of a
month or more; and YEARLY, to specify repeating events based on an month or more; and YEARLY, to specify repeating events based on an
interval of a year or more. interval of a year or more.
RFC 5545 iCalendar September 2009
The INTERVAL rule part contains a positive integer representing at The INTERVAL rule part contains a positive integer representing at
which intervals the recurrence rule repeats. The default value is which intervals the recurrence rule repeats. The default value is
"1", meaning every second for a SECONDLY rule, every minute for a "1", meaning every second for a SECONDLY rule, every minute for a
MINUTELY rule, every hour for an HOURLY rule, every day for a MINUTELY rule, every hour for an HOURLY rule, every day for a
DAILY rule, every week for a WEEKLY rule, every month for a DAILY rule, every week for a WEEKLY rule, every month for a
MONTHLY rule, and every year for a YEARLY rule. For example, MONTHLY rule, and every year for a YEARLY rule. For example,
within a DAILY rule, a value of "8" means every eight days. within a DAILY rule, a value of "8" means every eight days.
The UNTIL rule part defines a DATE or DATE-TIME value which bounds The UNTIL rule part defines a DATE or DATE-TIME value that bounds
the recurrence rule in an inclusive manner. If the value the recurrence rule in an inclusive manner. If the value
specified by UNTIL is synchronized with the specified recurrence, specified by UNTIL is synchronized with the specified recurrence,
this DATE or DATE-TIME becomes the last instance of the this DATE or DATE-TIME becomes the last instance of the
recurrence. The value of the UNTIL rule part MUST have the same recurrence. The value of the UNTIL rule part MUST have the same
value type as the "DTSTART" property. Furthermore, if the value type as the "DTSTART" property. Furthermore, if the
"DTSTART" property is specified as a date with local time, then "DTSTART" property is specified as a date with local time, then
the UNTIL rule part MUST also be specified as a date with local the UNTIL rule part MUST also be specified as a date with local
time. If the "DTSTART" property is specified as a date with UTC time. If the "DTSTART" property is specified as a date with UTC
time or a date with local time and time zone reference, then the time or a date with local time and time zone reference, then the
UNTIL rule part MUST be specified as a date with UTC time. In the UNTIL rule part MUST be specified as a date with UTC time. In the
case of the "STANDARD" and "DAYLIGHT" sub-components the UNTIL case of the "STANDARD" and "DAYLIGHT" sub-components the UNTIL
rule part MUST always be specified as a date with UTC time. If rule part MUST always be specified as a date with UTC time. If
specified as a DATE-TIME value, then it MUST be specified in a UTC specified as a DATE-TIME value, then it MUST be specified in a UTC
time format. If not present, and the COUNT rule part is also not time format. If not present, and the COUNT rule part is also not
present, the "RRULE" is considered to repeat forever. present, the "RRULE" is considered to repeat forever.
The COUNT rule part defines the number of occurrences at which to The COUNT rule part defines the number of occurrences at which to
range-bound the recurrence. The "DTSTART" property value always range-bound the recurrence. The "DTSTART" property value always
counts as the first occurrence. counts as the first occurrence.
The BYSECOND rule part specifies a COMMA character (US-ASCII The BYSECOND rule part specifies a COMMA-separated list of seconds
decimal 44) separated list of seconds within a minute. Valid within a minute. Valid values are 0 to 60. The BYMINUTE rule
values are 0 to 60. The BYMINUTE rule part specifies a COMMA part specifies a COMMA-separated list of minutes within an hour.
character (US-ASCII decimal 44) separated list of minutes within Valid values are 0 to 59. The BYHOUR rule part specifies a COMMA-
an hour. Valid values are 0 to 59. The BYHOUR rule part separated list of hours of the day. Valid values are 0 to 23.
specifies a COMMA character (US-ASCII decimal 44) separated list The BYSECOND, BYMINUTE and BYHOUR rule parts MUST NOT be specified
of hours of the day. Valid values are 0 to 23. The BYSECOND, when the associated "DTSTART" property has a DATE value type.
BYMINUTE and BYHOUR rule parts MUST NOT be specified when the These rule parts MUST be ignored in RECUR value that violate the
associated "DTSTART" property has a DATE value type. These rule above requirement (e.g., generated by applications that pre-date
parts MUST be ignored in RECUR value that violate the above this revision of iCalendar).
requirement (e.g., generated by applications that pre-date this
revision of iCalendar).
The BYDAY rule part specifies a COMMA character (US-ASCII decimal The BYDAY rule part specifies a COMMA-separated list of days of
44) separated list of days of the week; SU indicates Sunday; MO the week; SU indicates Sunday; MO indicates Monday; TU indicates
indicates Monday; TU indicates Tuesday; WE indicates Wednesday; TH Tuesday; WE indicates Wednesday; TH indicates Thursday; FR
indicates Thursday; FR indicates Friday; SA indicates Saturday. indicates Friday; and SA indicates Saturday.
Each BYDAY value can also be preceded by a positive (+n) or Each BYDAY value can also be preceded by a positive (+n) or
negative (-n) integer. If present, this indicates the nth negative (-n) integer. If present, this indicates the nth
occurrence of a specific day within the MONTHLY or YEARLY "RRULE". occurrence of a specific day within the MONTHLY or YEARLY "RRULE".
RFC 5545 iCalendar September 2009
For example, within a MONTHLY rule, +1MO (or simply 1MO) For example, within a MONTHLY rule, +1MO (or simply 1MO)
represents the first Monday within the month, whereas -1MO represents the first Monday within the month, whereas -1MO
represents the last Monday of the month. The numeric value in a represents the last Monday of the month. The numeric value in a
BYDAY rule part with the FREQ rule part set to YEARLY corresponds BYDAY rule part with the FREQ rule part set to YEARLY corresponds
to an offset within the month when the BYMONTH rule part is to an offset within the month when the BYMONTH rule part is
present, and corresponds to an offset within the year when the present, and corresponds to an offset within the year when the
BYWEEKNO or BYMONTH rule parts are present. If an integer BYWEEKNO or BYMONTH rule parts are present. If an integer
modifier is not present, it means all days of this type within the modifier is not present, it means all days of this type within the
specified frequency. For example, within a MONTHLY rule, MO specified frequency. For example, within a MONTHLY rule, MO
represents all Mondays within the month. The BYDAY rule part MUST represents all Mondays within the month. The BYDAY rule part MUST
NOT be specified with a numeric value when the FREQ rule part is NOT be specified with a numeric value when the FREQ rule part is
not set to MONTHLY or YEARLY. Furthermore, the BYDAY rule part not set to MONTHLY or YEARLY. Furthermore, the BYDAY rule part
MUST NOT be specified with a numeric value with the FREQ rule part MUST NOT be specified with a numeric value with the FREQ rule part
set to YEARLY when the BYWEEKNO rule part is specified. set to YEARLY when the BYWEEKNO rule part is specified.
The BYMONTHDAY rule part specifies a COMMA character (US-ASCII The BYMONTHDAY rule part specifies a COMMA-separated list of days
decimal 44) separated list of days of the month. Valid values are of the month. Valid values are 1 to 31 or -31 to -1. For
1 to 31 or -31 to -1. For example, -10 represents the tenth to example, -10 represents the tenth to the last day of the month.
the last day of the month. The BYMONTHDAY rule part MUST NOT be The BYMONTHDAY rule part MUST NOT be specified when the FREQ rule
specified when the FREQ rule part is set to WEEKLY. part is set to WEEKLY.
The BYYEARDAY rule part specifies a COMMA character (US-ASCII The BYYEARDAY rule part specifies a COMMA-separated list of days
decimal 44) separated list of days of the year. Valid values are of the year. Valid values are 1 to 366 or -366 to -1. For
1 to 366 or -366 to -1. For example, -1 represents the last day example, -1 represents the last day of the year (December 31st)
of the year (December 31st) and -306 represents the 306th to the and -306 represents the 306th to the last day of the year (March
last day of the year (March 1st). The BYYEARDAY rule part MUST 1st). The BYYEARDAY rule part MUST NOT be specified when the FREQ
NOT be specified when the FREQ rule part is set to DAILY, WEEKLY, rule part is set to DAILY, WEEKLY, or MONTHLY.
or MONTHLY.
The BYWEEKNO rule part specifies a COMMA character (US-ASCII The BYWEEKNO rule part specifies a COMMA-separated list of
decimal 44) separated list of ordinals specifying weeks of the ordinals specifying weeks of the year. Valid values are 1 to 53
year. Valid values are 1 to 53 or -53 to -1. This corresponds to or -53 to -1. This corresponds to weeks according to week
weeks according to week numbering as defined in [ISO.8601.2004]. numbering as defined in [ISO.8601.2004]. A week is defined as a
A week is defined as a seven day period, starting on the day of seven day period, starting on the day of the week defined to be
the week defined to be the week start (see WKST). Week number one the week start (see WKST). Week number one of the calendar year
of the calendar year is the first week which contains at least is the first week that contains at least four (4) days in that
four (4) days in that calendar year. This rule part MUST NOT be calendar year. This rule part MUST NOT be used when the FREQ rule
used when the FREQ rule part is set to anything other than YEARLY. part is set to anything other than YEARLY. For example, 3
For example, 3 represents the third week of the year. represents the third week of the year.
Note: Assuming a Monday week start, week 53 can only occur when Note: Assuming a Monday week start, week 53 can only occur when
Thursday is January 1 or if it is a leap year and Wednesday is Thursday is January 1 or if it is a leap year and Wednesday is
January 1. January 1.
The BYMONTH rule part specifies a COMMA character (US-ASCII The BYMONTH rule part specifies a COMMA-separated list of months
decimal 44) separated list of months of the year. Valid values of the year. Valid values are 1 to 12.
are 1 to 12.
The WKST rule part specifies the day on which the workweek starts. The WKST rule part specifies the day on which the workweek starts.
Valid values are MO, TU, WE, TH, FR, SA and SU. This is Valid values are MO, TU, WE, TH, FR, SA, and SU. This is
RFC 5545 iCalendar September 2009
significant when a WEEKLY "RRULE" has an interval greater than 1, significant when a WEEKLY "RRULE" has an interval greater than 1,
and a BYDAY rule part is specified. This is also significant when and a BYDAY rule part is specified. This is also significant when
in a YEARLY "RRULE" when a BYWEEKNO rule part is specified. The in a YEARLY "RRULE" when a BYWEEKNO rule part is specified. The
default value is MO. default value is MO.
The BYSETPOS rule part specifies a COMMA character (US-ASCII The BYSETPOS rule part specifies a COMMA-separated list of values
decimal 44) separated list of values which corresponds to the nth that corresponds to the nth occurrence within the set of
occurrence within the set of recurrence instances specified by the recurrence instances specified by the rule. BYSETPOS operates on
rule. BYSETPOS operates on a set of recurrence instances in one a set of recurrence instances in one interval of the recurrence
interval of the recurrence rule. For example, in a WEEKLY rule, rule. For example, in a WEEKLY rule, the interval would be one
the interval would be one week A set of recurrence instances week A set of recurrence instances starts at the beginning of the
starts at the beginning of the interval defined by the FREQ rule interval defined by the FREQ rule part. Valid values are 1 to 366
part. Valid values are 1 to 366 or -366 to -1. It MUST only be or -366 to -1. It MUST only be used in conjunction with another
used in conjunction with another BYxxx rule part. For example BYxxx rule part. For example "the last work day of the month"
"the last work day of the month" could be represented as: could be represented as:
FREQ=MONTHLY;BYDAY=MO,TU,WE,TH,FR;BYSETPOS=-1 FREQ=MONTHLY;BYDAY=MO,TU,WE,TH,FR;BYSETPOS=-1
Each BYSETPOS value can include a positive (+n) or negative (-n) Each BYSETPOS value can include a positive (+n) or negative (-n)
integer. If present, this indicates the nth occurrence of the integer. If present, this indicates the nth occurrence of the
specific occurrence within the set of occurences specified by the specific occurrence within the set of occurrences specified by the
rule. rule.
Recurrence rules may generate recurrence instances with invalid Recurrence rules may generate recurrence instances with an invalid
date (e.g., February 30) or nonexistent local time (e.g., 1:30 AM date (e.g., February 30) or nonexistent local time (e.g., 1:30 AM
on a day where the local time is moved forward by an hour at 1:00 on a day where the local time is moved forward by an hour at 1:00
AM). Such recurrence instances MUST be ignored and MUST NOT be AM). Such recurrence instances MUST be ignored and MUST NOT be
counted as part of the recurrence set. counted as part of the recurrence set.
Information, not contained in the rule, necessary to determine the Information, not contained in the rule, necessary to determine the
various recurrence instance start time and dates are derived from various recurrence instance start time and dates are derived from
the Start Time ("DTSTART") component attribute. For example, the Start Time ("DTSTART") component attribute. For example,
"FREQ=YEARLY;BYMONTH=1" doesn't specify a specific day within the "FREQ=YEARLY;BYMONTH=1" doesn't specify a specific day within the
month or a time. This information would be the same as what is month or a time. This information would be the same as what is
specified for "DTSTART". specified for "DTSTART".
BYxxx rule parts modify the recurrence in some manner. BYxxx rule BYxxx rule parts modify the recurrence in some manner. BYxxx rule
parts for a period of time which is the same or greater than the parts for a period of time that is the same or greater than the
frequency generally reduce or limit the number of occurrences of frequency generally reduce or limit the number of occurrences of
the recurrence generated. For example, "FREQ=DAILY;BYMONTH=1" the recurrence generated. For example, "FREQ=DAILY;BYMONTH=1"
reduces the number of recurrence instances from all days (if reduces the number of recurrence instances from all days (if
BYMONTH rule part is not present) to all days in January. BYxxx BYMONTH rule part is not present) to all days in January. BYxxx
rule parts for a period of time less than the frequency generally rule parts for a period of time less than the frequency generally
increase or expand the number of occurrences of the recurrence. increase or expand the number of occurrences of the recurrence.
For example, "FREQ=YEARLY;BYMONTH=1,2" increases the number of For example, "FREQ=YEARLY;BYMONTH=1,2" increases the number of
days within the yearly recurrence set from 1 (if BYMONTH rule part days within the yearly recurrence set from 1 (if BYMONTH rule part
is not present) to 2. is not present) to 2.
RFC 5545 iCalendar September 2009
If multiple BYxxx rule parts are specified, then after evaluating If multiple BYxxx rule parts are specified, then after evaluating
the specified FREQ and INTERVAL rule parts, the BYxxx rule parts the specified FREQ and INTERVAL rule parts, the BYxxx rule parts
are applied to the current set of evaluated occurrences in the are applied to the current set of evaluated occurrences in the
following order: BYMONTH, BYWEEKNO, BYYEARDAY, BYMONTHDAY, BYDAY, following order: BYMONTH, BYWEEKNO, BYYEARDAY, BYMONTHDAY, BYDAY,
BYHOUR, BYMINUTE, BYSECOND and BYSETPOS; then COUNT and UNTIL are BYHOUR, BYMINUTE, BYSECOND and BYSETPOS; then COUNT and UNTIL are
evaluated. evaluated.
The table below summarizes the dependency of BYxxx rule part The table below summarizes the dependency of BYxxx rule part
expand or limit behaviour on the FREQ rule part value. expand or limit behavior on the FREQ rule part value.
The term "N/A" means that the corresponding BYxxx rule part MUST The term "N/A" means that the corresponding BYxxx rule part MUST
NOT be used with the corresponding FREQ value. NOT be used with the corresponding FREQ value.
BYDAY has some special behaviour depending on the FREQ value and BYDAY has some special behavior depending on the FREQ value and
this is described in separate notes below the table. this is described in separate notes below the table.
+----------+--------+--------+-------+-------+------+-------+------+ +----------+--------+--------+-------+-------+------+-------+------+
| |SECONDLY|MINUTELY|HOURLY |DAILY |WEEKLY|MONTHLY|YEARLY| | |SECONDLY|MINUTELY|HOURLY |DAILY |WEEKLY|MONTHLY|YEARLY|
+----------+--------+--------+-------+-------+------+-------+------+ +----------+--------+--------+-------+-------+------+-------+------+
|BYMONTH |Limit |Limit |Limit |Limit |Limit |Limit |Expand| |BYMONTH |Limit |Limit |Limit |Limit |Limit |Limit |Expand|
+----------+--------+--------+-------+-------+------+-------+------+ +----------+--------+--------+-------+-------+------+-------+------+
|BYWEEKNO |N/A |N/A |N/A |N/A |N/A |N/A |Expand| |BYWEEKNO |N/A |N/A |N/A |N/A |N/A |N/A |Expand|
+----------+--------+--------+-------+-------+------+-------+------+ +----------+--------+--------+-------+-------+------+-------+------+
|BYYEARDAY |Limit |Limit |Limit |N/A |N/A |N/A |Expand| |BYYEARDAY |Limit |Limit |Limit |N/A |N/A |N/A |Expand|
skipping to change at page 47, line 27 skipping to change at page 44, line 45
+----------+--------+--------+-------+-------+------+-------+------+ +----------+--------+--------+-------+-------+------+-------+------+
|BYHOUR |Limit |Limit |Limit |Expand |Expand|Expand |Expand| |BYHOUR |Limit |Limit |Limit |Expand |Expand|Expand |Expand|
+----------+--------+--------+-------+-------+------+-------+------+ +----------+--------+--------+-------+-------+------+-------+------+
|BYMINUTE |Limit |Limit |Expand |Expand |Expand|Expand |Expand| |BYMINUTE |Limit |Limit |Expand |Expand |Expand|Expand |Expand|
+----------+--------+--------+-------+-------+------+-------+------+ +----------+--------+--------+-------+-------+------+-------+------+
|BYSECOND |Limit |Expand |Expand |Expand |Expand|Expand |Expand| |BYSECOND |Limit |Expand |Expand |Expand |Expand|Expand |Expand|
+----------+--------+--------+-------+-------+------+-------+------+ +----------+--------+--------+-------+-------+------+-------+------+
|BYSETPOS |Limit |Limit |Limit |Limit |Limit |Limit |Limit | |BYSETPOS |Limit |Limit |Limit |Limit |Limit |Limit |Limit |
+----------+--------+--------+-------+-------+------+-------+------+ +----------+--------+--------+-------+-------+------+-------+------+
Note 1: Limit if BYMONTHDAY is present, otherwise special expand Note 1: Limit if BYMONTHDAY is present; otherwise, special expand
for MONTHLY. for MONTHLY.
Note 2: Limit if BYYEARDAY or BYMONTHDAY is present, otherwise Note 2: Limit if BYYEARDAY or BYMONTHDAY is present; otherwise,
special expand for WEEKLY if BYWEEKNO present, otherwise special expand for WEEKLY if BYWEEKNO present; otherwise,
special expand for MONTHLY if BYMONTH present, otherwise special expand for MONTHLY if BYMONTH present; otherwise,
special expand for YEARLY. special expand for YEARLY.
RFC 5545 iCalendar September 2009
Here is an example of evaluating multiple BYxxx rule parts. Here is an example of evaluating multiple BYxxx rule parts.
DTSTART;TZID=America/New_York:19970105T083000 DTSTART;TZID=America/New_York:19970105T083000
RRULE:FREQ=YEARLY;INTERVAL=2;BYMONTH=1;BYDAY=SU;BYHOUR=8,9; RRULE:FREQ=YEARLY;INTERVAL=2;BYMONTH=1;BYDAY=SU;BYHOUR=8,9;
BYMINUTE=30 BYMINUTE=30
First, the "INTERVAL=2" would be applied to "FREQ=YEARLY" to First, the "INTERVAL=2" would be applied to "FREQ=YEARLY" to
arrive at "every other year". Then, "BYMONTH=1" would be applied arrive at "every other year". Then, "BYMONTH=1" would be applied
to arrive at "every January, every other year". Then, "BYDAY=SU" to arrive at "every January, every other year". Then, "BYDAY=SU"
would be applied to arrive at "every Sunday in January, every would be applied to arrive at "every Sunday in January, every
other year". Then, "BYHOUR=8,9" would be applied to arrive at other year". Then, "BYHOUR=8,9" would be applied to arrive at
"every Sunday in January at 8 AM and 9 AM, every other year". "every Sunday in January at 8 AM and 9 AM, every other year".
Then, "BYMINUTE=30" would be applied to arrive at "every Sunday in Then, "BYMINUTE=30" would be applied to arrive at "every Sunday in
January at 8:30 AM and 9:30 AM, every other year". Then, lacking January at 8:30 AM and 9:30 AM, every other year". Then, lacking
information from "RRULE", the second is derived from "DTSTART", to information from "RRULE", the second is derived from "DTSTART", to
end up in "every Sunday in January at 8:30:00 AM and 9:30:00 AM, end up in "every Sunday in January at 8:30:00 AM and 9:30:00 AM,
every other year". Similarly, if the BYMINUTE, BYHOUR, BYDAY, every other year". Similarly, if the BYMINUTE, BYHOUR, BYDAY,
BYMONTHDAY or BYMONTH rule part were missing, the appropriate BYMONTHDAY, or BYMONTH rule part were missing, the appropriate
minute, hour, day or month would have been retrieved from the minute, hour, day, or month would have been retrieved from the
"DTSTART" property. "DTSTART" property.
If the computed local start time of a recurrence instance does not If the computed local start time of a recurrence instance does not
exist, or occurs more than once, for the specified time zone, the exist, or occurs more than once, for the specified time zone, the
time of the recurrence instance is interpreted in the same manner time of the recurrence instance is interpreted in the same manner
as an explicit DATE-TIME value describing that date and time, as as an explicit DATE-TIME value describing that date and time, as
specified in Section 3.3.5. specified in Section 3.3.5.
No additional content value encoding (i.e., BACKSLASH character No additional content value encoding (i.e., BACKSLASH character
encoding, see Section 3.3.11) is defined for this value type. encoding, see Section 3.3.11) is defined for this value type.
Example: The following is a rule which specifies 10 occurences which Example: The following is a rule that specifies 10 occurrences that
occur every other day: occur every other day:
FREQ=DAILY;COUNT=10;INTERVAL=2 FREQ=DAILY;COUNT=10;INTERVAL=2
There are other examples specified in Section 3.8.5.3. There are other examples specified in Section 3.8.5.3.
3.3.11. Text 3.3.11. Text
Value Name: TEXT Value Name: TEXT
Purpose: This value type is used to identify values that contain Purpose: This value type is used to identify values that contain
human readable text. human-readable text.
Format Definition: This value type is defined by the following Format Definition: This value type is defined by the following
notation. notation:
text = *(TSAFE-CHAR / ":" / DQUOTE / ESCAPED-CHAR) RFC 5545 iCalendar September 2009
; Folded according to description above
ESCAPED-CHAR = ("\\" / "\;" / "\," / "\N" / "\n") text = *(TSAFE-CHAR / ":" / DQUOTE / ESCAPED-CHAR)
; \\ encodes \, \N or \n encodes newline ; Folded according to description above
; \; encodes ;, \, encodes ,
TSAFE-CHAR = WSP / %x21 / %x23-2B / %x2D-39 / %x3C-5B / ESCAPED-CHAR = ("\\" / "\;" / "\," / "\N" / "\n")
%x5D-7E / NON-US-ASCII ; \\ encodes \, \N or \n encodes newline
; Any character except CONTROLs not needed by the current ; \; encodes ;, \, encodes ,
; character set, DQUOTE, ";", ":", "\", ","
TSAFE-CHAR = WSP / %x21 / %x23-2B / %x2D-39 / %x3C-5B /
%x5D-7E / NON-US-ASCII
; Any character except CONTROLs not needed by the current
; character set, DQUOTE, ";", ":", "\", ","
Description: If the property permits, multiple TEXT values are Description: If the property permits, multiple TEXT values are
specified by a COMMA character (US-ASCII decimal 44) separated specified by a COMMA-separated list of values.
list of values.
The language in which the text is represented can be controlled by The language in which the text is represented can be controlled by
the "LANGUAGE" property parameter. the "LANGUAGE" property parameter.
An intentional formatted text line break MUST only be included in An intentional formatted text line break MUST only be included in
a "TEXT" property value by representing the line break with the a "TEXT" property value by representing the line break with the
character sequence of BACKSLASH (US-ASCII decimal 92), followed by character sequence of BACKSLASH, followed by a LATIN SMALL LETTER
a LATIN SMALL LETTER N (US-ASCII decimal 110) or a LATIN CAPITAL N or a LATIN CAPITAL LETTER N, that is "\n" or "\N".
LETTER N (US-ASCII decimal 78), that is "\n" or "\N".
The "TEXT" property values may also contain special characters The "TEXT" property values may also contain special characters
that are used to signify delimiters, such as a COMMA character for that are used to signify delimiters, such as a COMMA character for
lists of values or a SEMICOLON character for structured values. lists of values or a SEMICOLON character for structured values.
In order to support the inclusion of these special characters in In order to support the inclusion of these special characters in
"TEXT" property values, they MUST be escaped with a BACKSLASH "TEXT" property values, they MUST be escaped with a BACKSLASH
character. A BACKSLASH character (US-ASCII decimal 92) in a character. A BACKSLASH character in a "TEXT" property value MUST
"TEXT" property value MUST be escaped with another BACKSLASH be escaped with another BACKSLASH character. A COMMA character in
character. A COMMA character in a "TEXT" property value MUST be a "TEXT" property value MUST be escaped with a BACKSLASH
escaped with a BACKSLASH character (US-ASCII decimal 92). A character. A SEMICOLON character in a "TEXT" property value MUST
SEMICOLON character in a "TEXT" property value MUST be escaped be escaped with a BACKSLASH character. However, a COLON character
with a BACKSLASH character (US-ASCII decimal 92). However, a in a "TEXT" property value SHALL NOT be escaped with a BACKSLASH
COLON character in a "TEXT" property value SHALL NOT be escaped character.
with a BACKSLASH character.
Example: A multiple line value of: Example: A multiple line value of:
Project XYZ Final Review Project XYZ Final Review
Conference Room - 3B Conference Room - 3B
Come Prepared. Come Prepared.
would be represented as: would be represented as:
Project XYZ Final Review\nConference Room - 3B\nCome Prepared. Project XYZ Final Review\nConference Room - 3B\nCome Prepared.
RFC 5545 iCalendar September 2009
3.3.12. Time 3.3.12. Time
Value Name: TIME Value Name: TIME
Purpose: This value type is used to identify values that contain a Purpose: This value type is used to identify values that contain a
time of day. time of day.
Format Definition: This value type is defined by the following Format Definition: This value type is defined by the following
notation: notation:
time = time-hour time-minute time-second [time-utc] time = time-hour time-minute time-second [time-utc]
time-hour = 2DIGIT ;00-23 time-hour = 2DIGIT ;00-23
time-minute = 2DIGIT ;00-59 time-minute = 2DIGIT ;00-59
time-second = 2DIGIT ;00-60 time-second = 2DIGIT ;00-60
;The "60" value is used to account for positive "leap" seconds. ;The "60" value is used to account for positive "leap" seconds.
time-utc = "Z" time-utc = "Z"
Description: If the property permits, multiple "time" values are Description: If the property permits, multiple "time" values are
specified by a COMMA character (US-ASCII decimal 44) separated specified by a COMMA-separated list of values. No additional
list of values. No additional content value encoding (i.e., content value encoding (i.e., BACKSLASH character encoding, see
BACKSLASH character encoding, see Section 3.3.11) is defined for Section 3.3.11) is defined for this value type.
this value type.
The "TIME" value type is used to identify values that contain a The "TIME" value type is used to identify values that contain a
time of day. The format is based on the [ISO.8601.2004] complete time of day. The format is based on the [ISO.8601.2004] complete
representation, basic format for a time of day. The text format representation, basic format for a time of day. The text format
consists of a two-digit 24-hour of the day (i.e., values 00-23), consists of a two-digit, 24-hour of the day (i.e., values 00-23),
two-digit minute in the hour (i.e., values 00-59), and two-digit two-digit minute in the hour (i.e., values 00-59), and two-digit
seconds in the minute (i.e., values 00-60). The seconds value of seconds in the minute (i.e., values 00-60). The seconds value of
60 MUST only be used to account for positive "leap" seconds. 60 MUST only be used to account for positive "leap" seconds.
Fractions of a second are not supported by this format. Fractions of a second are not supported by this format.
In parallel to the "DATE-TIME" definition above, the "TIME" value In parallel to the "DATE-TIME" definition above, the "TIME" value
type expresses time values in three forms: type expresses time values in three forms:
The form of time with UTC offset MUST NOT be used. For example, The form of time with UTC offset MUST NOT be used. For example,
the following is not valid for a time value: the following is not valid for a time value:
230000-0800 ;Invalid time format 230000-0800 ;Invalid time format
FORM #1 LOCAL TIME FORM #1 LOCAL TIME
The local time form is simply a time value that does not contain The local time form is simply a time value that does not contain
the UTC designator nor does it reference a time zone. For the UTC designator nor does it reference a time zone. For
example, 11:00 PM: example, 11:00 PM:
230000 230000
RFC 5545 iCalendar September 2009
Time values of this type are said to be "floating" and are not Time values of this type are said to be "floating" and are not
bound to any time zone in particular. They are used to represent bound to any time zone in particular. They are used to represent
the same hour, minute, and second value regardless of which time the same hour, minute, and second value regardless of which time
zone is currently being observed. For example, an event can be zone is currently being observed. For example, an event can be
defined that indicates that an individual will be busy from 11:00 defined that indicates that an individual will be busy from 11:00
AM to 1:00 PM every day, no matter which time zone the person is AM to 1:00 PM every day, no matter which time zone the person is
in. In these cases, a local time can be specified. The recipient in. In these cases, a local time can be specified. The recipient
of an iCalendar object with a property value consisting of a local of an iCalendar object with a property value consisting of a local
time, without any relative time zone information, SHOULD interpret time, without any relative time zone information, SHOULD interpret
skipping to change at page 51, line 22 skipping to change at page 48, line 33
time zone reference MUST be specified. time zone reference MUST be specified.
The use of local time in a TIME value without the "TZID" property The use of local time in a TIME value without the "TZID" property
parameter is to be interpreted as floating time, regardless of the parameter is to be interpreted as floating time, regardless of the
existence of "VTIMEZONE" calendar components in the iCalendar existence of "VTIMEZONE" calendar components in the iCalendar
object. object.
FORM #2: UTC TIME FORM #2: UTC TIME
UTC time, or absolute time, is identified by a LATIN CAPITAL UTC time, or absolute time, is identified by a LATIN CAPITAL
LETTER Z suffix character (US-ASCII decimal 90), the UTC LETTER Z suffix character, the UTC designator, appended to the
designator, appended to the time value. For example, the time value. For example, the following represents 07:00 AM UTC:
following represents 07:00 AM UTC:
070000Z 070000Z
The "TZID" property parameter MUST NOT be applied to TIME The "TZID" property parameter MUST NOT be applied to TIME
properties whose time values are specified in UTC. properties whose time values are specified in UTC.
FORM #3: LOCAL TIME AND TIME ZONE REFERENCE FORM #3: LOCAL TIME AND TIME ZONE REFERENCE
The local time with reference to time zone information form is The local time with reference to time zone information form is
identified by the use the "TZID" property parameter to reference identified by the use the "TZID" property parameter to reference
the appropriate time zone definition. "TZID" is discussed in the appropriate time zone definition. "TZID" is discussed in
detail in Section 3.2.19. detail in Section 3.2.19.
Example: The following represents 8:30 AM in New York in Winter, Example: The following represents 8:30 AM in New York in winter,
five hours behind UTC, in each of the three formats: five hours behind UTC, in each of the three formats:
083000 083000
133000Z 133000Z
TZID=America/New_York:083000
TZID=America/New_York:083000 RFC 5545 iCalendar September 2009
3.3.13. URI 3.3.13. URI
Value Name: URI Value Name: URI
Purpose: This value type is used to identify values that contain a Purpose: This value type is used to identify values that contain a
uniform resource identifier (URI) type of reference to the uniform resource identifier (URI) type of reference to the
property value. property value.
Format Definition: This value type is defined by the following Format Definition: This value type is defined by the following
notation: notation:
uri = <As defined in section 3 of [RFC3986]> uri = <As defined in Section 3 of [RFC3986]>
Description: This value type might be used to reference binary Description: This value type might be used to reference binary
information, for values that are large, or otherwise undesirable information, for values that are large, or otherwise undesirable
to include directly in the iCalendar object. to include directly in the iCalendar object.
Property values with this value type MUST follow the generic URI Property values with this value type MUST follow the generic URI
syntax defined in [RFC3986]. syntax defined in [RFC3986].
When a property parameter value is a URI value type, the URI MUST When a property parameter value is a URI value type, the URI MUST
be specified as a quoted-string value. be specified as a quoted-string value.
No additional content value encoding (i.e., BACKSLASH character No additional content value encoding (i.e., BACKSLASH character
encoding, see Section 3.3.11) is defined for this value type. encoding, see Section 3.3.11) is defined for this value type.
Example: The following is a URI for a network file: Example: The following is a URI for a network file:
http://example.com/my-report.txt http://example.com/my-report.txt
3.3.14. UTC Offset 3.3.14. UTC Offset
Value Name: UTC-OFFSET Value Name: UTC-OFFSET
Purpose: This value type is used to identify properties that contain Purpose: This value type is used to identify properties that contain
an offset from UTC to local time. an offset from UTC to local time.
Format Definition: This value type is defined by the following Format Definition: This value type is defined by the following
notation: notation:
utc-offset = time-numzone utc-offset = time-numzone
time-numzone = ("+" / "-") time-hour time-minute [time-second] time-numzone = ("+" / "-") time-hour time-minute [time-second]
Description: The PLUS SIGN (US-ASCII decimal 43) character MUST be Description: The PLUS SIGN character MUST be specified for positive
specified for positive UTC offsets (i.e., ahead of UTC). The UTC offsets (i.e., ahead of UTC). The HYPHEN-MINUS character MUST
HYPHEN-MINUS character (US-ASCII decimal 45) MUST be specified for be specified for negative UTC offsets (i.e., behind of UTC). The
negative UTC offsets (i.e., behind of UTC). The value of "-0000"
and "-000000" are not allowed. The time-second, if present, MUST RFC 5545 iCalendar September 2009
NOT be 60; if absent, it defaults to zero.
value of "-0000" and "-000000" are not allowed. The time-second,
if present, MUST NOT be 60; if absent, it defaults to zero.
No additional content value encoding (i.e., BACKSLASH character No additional content value encoding (i.e., BACKSLASH character
encoding, see Section 3.3.11) is defined for this value type. encoding, see Section 3.3.11) is defined for this value type.
Example: The following UTC offsets are given for standard time for Example: The following UTC offsets are given for standard time for
New York (five hours behind UTC) and Geneva (one hour ahead of New York (five hours behind UTC) and Geneva (one hour ahead of
UTC): UTC):
-0500 -0500
+0100 +0100
3.4. iCalendar Object 3.4. iCalendar Object
The Calendaring and Scheduling Core Object is a collection of The Calendaring and Scheduling Core Object is a collection of
calendaring and scheduling information. Typically, this information calendaring and scheduling information. Typically, this information
will consist of an iCalendar stream with a single iCalendar object. will consist of an iCalendar stream with a single iCalendar object.
However, multiple iCalendar objects can be sequentially grouped However, multiple iCalendar objects can be sequentially grouped
together in an iCalendar stream. The first line and last line of the together in an iCalendar stream. The first line and last line of the
iCalendar object MUST contain a pair of iCalendar object delimiter iCalendar object MUST contain a pair of iCalendar object delimiter
strings. The syntax for an iCalendar stream is as follows: strings. The syntax for an iCalendar stream is as follows:
icalstream = 1*icalobject icalstream = 1*icalobject
icalobject = "BEGIN" ":" "VCALENDAR" CRLF icalobject = "BEGIN" ":" "VCALENDAR" CRLF
icalbody icalbody
"END" ":" "VCALENDAR" CRLF "END" ":" "VCALENDAR" CRLF
The following is a simple example of an iCalendar object: The following is a simple example of an iCalendar object:
BEGIN:VCALENDAR BEGIN:VCALENDAR
VERSION:2.0 VERSION:2.0
PRODID:-//hacksw/handcal//NONSGML v1.0//EN PRODID:-//hacksw/handcal//NONSGML v1.0//EN
BEGIN:VEVENT BEGIN:VEVENT
UID:19970610T172345Z-AF23B2@example.com UID:19970610T172345Z-AF23B2@example.com
DTSTAMP:19970610T172345Z DTSTAMP:19970610T172345Z
DTSTART:19970714T170000Z DTSTART:19970714T170000Z
DTEND:19970715T040000Z DTEND:19970715T040000Z
SUMMARY:Bastille Day Party SUMMARY:Bastille Day Party
END:VEVENT END:VEVENT
END:VCALENDAR END:VCALENDAR
RFC 5545 iCalendar September 2009
3.5. Property 3.5. Property
A property is the definition of an individual attribute describing a A property is the definition of an individual attribute describing a
calendar object or a calendar component. A property takes the form calendar object or a calendar component. A property takes the form
defined by the "contentline" notation defined in Section 3.1. defined by the "contentline" notation defined in Section 3.1.
The following is an example of a property: The following is an example of a property:
DTSTART:19960415T133000Z DTSTART:19960415T133000Z
This memo imposes no ordering of properties within an iCalendar This memo imposes no ordering of properties within an iCalendar
object. object.
Property names, parameter names and enumerated parameter values are Property names, parameter names, and enumerated parameter values are
case insensitive. For example, the property name "DUE" is the same case-insensitive. For example, the property name "DUE" is the same
as "due" and "Due", DTSTART;TZID=America/New_York:19980714T120000 is as "due" and "Due", DTSTART;TZID=America/New_York:19980714T120000 is
the same as DtStart;TzID=America/New_York:19980714T120000. the same as DtStart;TzID=America/New_York:19980714T120000.
3.6. Calendar Components 3.6. Calendar Components
The body of the iCalendar object consists of a sequence of calendar The body of the iCalendar object consists of a sequence of calendar
properties and one or more calendar components. The calendar properties and one or more calendar components. The calendar
properties are attributes that apply to the calendar object as a properties are attributes that apply to the calendar object as a
whole. The calendar components are collections of properties that whole. The calendar components are collections of properties that
express a particular calendar semantic. For example, the calendar express a particular calendar semantic. For example, the calendar
component can specify an event, a to-do, a journal entry, time zone component can specify an event, a to-do, a journal entry, time zone
information, free/busy time information, or an alarm. information, free/busy time information, or an alarm.
The body of the iCalendar object is defined by the following The body of the iCalendar object is defined by the following
notation: notation:
icalbody = calprops component icalbody = calprops component
calprops = *( calprops = *(
; ;
; the following are REQUIRED, ; The following are REQUIRED,
; but MUST NOT occur more than once ; but MUST NOT occur more than once.
; ;
prodid / version / prodid / version /
; ;
; the following are OPTIONAL, ; The following are OPTIONAL,
; but MUST NOT occur more than once ; but MUST NOT occur more than once.
; ;
calscale / method / calscale / method /
; ;
; the following are OPTIONAL, ; The following are OPTIONAL,
; and MAY occur more than once ; and MAY occur more than once.
; ;
x-prop / iana-prop
;
)
component = 1*(eventc / todoc / journalc / freebusyc / RFC 5545 iCalendar September 2009
timezonec / iana-comp / x-comp)
iana-comp = "BEGIN" ":" iana-token CRLF x-prop / iana-prop
1*contentline ;
"END" ":" iana-token CRLF )
x-comp = "BEGIN" ":" x-name CRLF component = 1*(eventc / todoc / journalc / freebusyc /
1*contentline timezonec / iana-comp / x-comp)
"END" ":" x-name CRLF
iana-comp = "BEGIN" ":" iana-token CRLF
1*contentline
"END" ":" iana-token CRLF
x-comp = "BEGIN" ":" x-name CRLF
1*contentline
"END" ":" x-name CRLF
An iCalendar object MUST include the "PRODID" and "VERSION" calendar An iCalendar object MUST include the "PRODID" and "VERSION" calendar
properties. In addition, it MUST include at least one calendar properties. In addition, it MUST include at least one calendar
component. Special forms of iCalendar objects are possible to component. Special forms of iCalendar objects are possible to
publish just busy time (i.e., only a "VFREEBUSY" calendar component) publish just busy time (i.e., only a "VFREEBUSY" calendar component)
or time zone (i.e., only a "VTIMEZONE" calendar component) or time zone (i.e., only a "VTIMEZONE" calendar component)
information. In addition, a complex iCalendar object that is used to information. In addition, a complex iCalendar object that is used to
capture a complete snapshot of the contents of a calendar is possible capture a complete snapshot of the contents of a calendar is possible
(e.g., composite of many different calendar components). More (e.g., composite of many different calendar components). More
commonly, an iCalendar object will consist of just a single "VEVENT", commonly, an iCalendar object will consist of just a single "VEVENT",
"VTODO" or "VJOURNAL" calendar component. Applications MUST ignore "VTODO", or "VJOURNAL" calendar component. Applications MUST ignore
x-comp and iana-comp they don't recognized. Applications that x-comp and iana-comp values they don't recognize. Applications that
support importing iCalendar objects SHOULD support all of the support importing iCalendar objects SHOULD support all of the
component types defined in this document, and SHOULD NOT silently component types defined in this document, and SHOULD NOT silently
drop any components as that can lead to user data loss. drop any components as that can lead to user data loss.
3.6.1. Event Component 3.6.1. Event Component
Component Name: VEVENT Component Name: VEVENT
Purpose: Provide a grouping of component properties that describe an Purpose: Provide a grouping of component properties that describe an
event. event.
Format Definition: A "VEVENT" calendar component is defined by the Format Definition: A "VEVENT" calendar component is defined by the
following notation: following notation:
eventc = "BEGIN" ":" "VEVENT" CRLF eventc = "BEGIN" ":" "VEVENT" CRLF
eventprop *alarmc eventprop *alarmc
"END" ":" "VEVENT" CRLF "END" ":" "VEVENT" CRLF
eventprop = *( eventprop = *(
; ;
; the following are REQUIRED, ; The following are REQUIRED,
; but MUST NOT occur more than once ; but MUST NOT occur more than once.
;
dtstamp / uid / RFC 5545 iCalendar September 2009
;
; the following is REQUIRED if the component ;
; appears in an iCalendar object that doesn't dtstamp / uid /
; specify the "METHOD" property, otherwise it ;
; is OPTIONAL, in any case it MUST NOT occur ; The following is REQUIRED if the component
; more than once ; appears in an iCalendar object that doesn't
; ; specify the "METHOD" property; otherwise, it
dtstart / ; is OPTIONAL; in any case, it MUST NOT occur
; ; more than once.
; the following are OPTIONAL, ;
; but MUST NOT occur more than once dtstart /
; ;
class / created / description / geo / ; The following are OPTIONAL,
last-mod / location / organizer / priority / ; but MUST NOT occur more than once.
seq / status / summary / transp / ;
url / recurid / class / created / description / geo /
; last-mod / location / organizer / priority /
; the following is OPTIONAL, seq / status / summary / transp /
; but SHOULD NOT occur more than once url / recurid /
; ;
rrule / ; The following is OPTIONAL,
; ; but SHOULD NOT occur more than once.
; either 'dtend' or 'duration' MAY appear in ;
; a 'eventprop', but 'dtend' and 'duration' rrule /
; MUST NOT occur in the same 'eventprop' ;
; ; Either 'dtend' or 'duration' MAY appear in
dtend / duration / ; a 'eventprop', but 'dtend' and 'duration'
; ; MUST NOT occur in the same 'eventprop'.
; the following are OPTIONAL, ;
; and MAY occur more than once dtend / duration /
; ;
attach / attendee / categories / comment / ; The following are OPTIONAL,
contact / exdate / rstatus / related / ; and MAY occur more than once.
resources / rdate / x-prop / iana-prop ;
; attach / attendee / categories / comment /
) contact / exdate / rstatus / related /
resources / rdate / x-prop / iana-prop
;
)
Description: A "VEVENT" calendar component is a grouping of Description: A "VEVENT" calendar component is a grouping of
component properties, and possibly including "VALARM" calendar component properties, possibly including "VALARM" calendar
components, that represents a scheduled amount of time on a components, that represents a scheduled amount of time on a
calendar. For example, it can be an activity; such as a one-hour calendar. For example, it can be an activity; such as a one-hour
long, department meeting from 8:00 AM to 9:00 AM, tomorrow. long, department meeting from 8:00 AM to 9:00 AM, tomorrow.
Generally, an event will take up time on an individual calendar. Generally, an event will take up time on an individual calendar.
Hence, the event will appear as an opaque interval in a search for Hence, the event will appear as an opaque interval in a search for
busy time. Alternately, the event can have its Time Transparency busy time. Alternately, the event can have its Time Transparency
RFC 5545 iCalendar September 2009
set to "TRANSPARENT" in order to prevent blocking of the event in set to "TRANSPARENT" in order to prevent blocking of the event in
searches for busy time. searches for busy time.
The "VEVENT" is also the calendar component used to specify an The "VEVENT" is also the calendar component used to specify an
anniversary or daily reminder within a calendar. These events anniversary or daily reminder within a calendar. These events
have a DATE value type for the "DTSTART" property instead of the have a DATE value type for the "DTSTART" property instead of the
default value type of DATE-TIME. If such a "VEVENT" has a "DTEND" default value type of DATE-TIME. If such a "VEVENT" has a "DTEND"
property, it MUST be specified as a DATE value also. The property, it MUST be specified as a DATE value also. The
anniversary type of "VEVENT" can span more than one date (i.e., anniversary type of "VEVENT" can span more than one date (i.e.,
"DTEND" property value is set to a calendar date after the "DTEND" property value is set to a calendar date after the
skipping to change at page 59, line 5 skipping to change at page 54, line 41
The "VEVENT" calendar component cannot be nested within another The "VEVENT" calendar component cannot be nested within another
calendar component. However, "VEVENT" calendar components can be calendar component. However, "VEVENT" calendar components can be
related to each other or to a "VTODO" or to a "VJOURNAL" calendar related to each other or to a "VTODO" or to a "VJOURNAL" calendar
component with the "RELATED-TO" property. component with the "RELATED-TO" property.
Example: The following is an example of the "VEVENT" calendar Example: The following is an example of the "VEVENT" calendar
component used to represent a meeting that will also be opaque to component used to represent a meeting that will also be opaque to
searches for busy time: searches for busy time:
BEGIN:VEVENT BEGIN:VEVENT
UID:19970901T130000Z-123401@example.com UID:19970901T130000Z-123401@example.com
DTSTAMP:19970901T130000Z DTSTAMP:19970901T130000Z
DTSTART:19970903T163000Z DTSTART:19970903T163000Z
DTEND:19970903T190000Z DTEND:19970903T190000Z
SUMMARY:Annual Employee Review SUMMARY:Annual Employee Review
CLASS:PRIVATE CLASS:PRIVATE
CATEGORIES:BUSINESS,HUMAN RESOURCES CATEGORIES:BUSINESS,HUMAN RESOURCES
END:VEVENT END:VEVENT
The following is an example of the "VEVENT" calendar component The following is an example of the "VEVENT" calendar component
used to represent a reminder that will not be opaque, but rather used to represent a reminder that will not be opaque, but rather
transparent, to searches for busy time: transparent, to searches for busy time:
BEGIN:VEVENT RFC 5545 iCalendar September 2009
UID:19970901T130000Z-123402@example.com
DTSTAMP:19970901T130000Z BEGIN:VEVENT
DTSTART:19970401T163000Z UID:19970901T130000Z-123402@example.com
DTEND:19970402T010000Z DTSTAMP:19970901T130000Z
SUMMARY:Laurel is in sensitivity awareness class. DTSTART:19970401T163000Z
CLASS:PUBLIC DTEND:19970402T010000Z
CATEGORIES:BUSINESS,HUMAN RESOURCES SUMMARY:Laurel is in sensitivity awareness class.
TRANSP:TRANSPARENT CLASS:PUBLIC
END:VEVENT CATEGORIES:BUSINESS,HUMAN RESOURCES
TRANSP:TRANSPARENT
END:VEVENT
The following is an example of the "VEVENT" calendar component The following is an example of the "VEVENT" calendar component
used to represent an anniversary that will occur annually. used to represent an anniversary that will occur annually:
BEGIN:VEVENT BEGIN:VEVENT
UID:19970901T130000Z-123403@example.com UID:19970901T130000Z-123403@example.com
DTSTAMP:19970901T130000Z DTSTAMP:19970901T130000Z
DTSTART;VALUE=DATE:19971102 DTSTART;VALUE=DATE:19971102
SUMMARY:Our Blissful Anniversary SUMMARY:Our Blissful Anniversary
TRANSP:TRANSPARENT TRANSP:TRANSPARENT
CLASS:CONFIDENTIAL CLASS:CONFIDENTIAL
CATEGORIES:ANNIVERSARY,PERSONAL,SPECIAL OCCASION CATEGORIES:ANNIVERSARY,PERSONAL,SPECIAL OCCASION
RRULE:FREQ=YEARLY RRULE:FREQ=YEARLY
END:VEVENT END:VEVENT
The following is an example of the "VEVENT" calendar component The following is an example of the "VEVENT" calendar component
used to represent a multi-day event scheduled from June 28th, 2007 used to represent a multi-day event scheduled from June 28th, 2007
to July 8th, 2007 inclusively. Note that the "DTEND" property is to July 8th, 2007 inclusively. Note that the "DTEND" property is
set to July 9th, 2007, since the "DTEND" property specifies the set to July 9th, 2007, since the "DTEND" property specifies the
non-inclusive end of the event. non-inclusive end of the event.
BEGIN:VEVENT BEGIN:VEVENT
UID:20070423T123432Z-541111@example.com UID:20070423T123432Z-541111@example.com
DTSTAMP:20070423T123432Z DTSTAMP:20070423T123432Z
DTSTART;VALUE=DATE:20070628 DTSTART;VALUE=DATE:20070628
DTEND;VALUE=DATE:20070709 DTEND;VALUE=DATE:20070709
SUMMARY:Festival International de Jazz de Montreal SUMMARY:Festival International de Jazz de Montreal
TRANSP:TRANSPARENT TRANSP:TRANSPARENT
END:VEVENT END:VEVENT
3.6.2. To-do Component 3.6.2. To-Do Component
Component Name: VTODO Component Name: VTODO
Purpose: Provide a grouping of calendar properties that describe a Purpose: Provide a grouping of calendar properties that describe a
to-do. to-do.
RFC 5545 iCalendar September 2009
Format Definition: A "VTODO" calendar component is defined by the Format Definition: A "VTODO" calendar component is defined by the
following notation: following notation:
todoc = "BEGIN" ":" "VTODO" CRLF todoc = "BEGIN" ":" "VTODO" CRLF
todoprop *alarmc todoprop *alarmc
"END" ":" "VTODO" CRLF "END" ":" "VTODO" CRLF
todoprop = *( todoprop = *(
; ;
; the following are REQUIRED, ; The following are REQUIRED,
; but MUST NOT occur more than once ; but MUST NOT occur more than once.
; ;
dtstamp / uid / dtstamp / uid /
; ;
; the following are OPTIONAL, ; The following are OPTIONAL,
; but MUST NOT occur more than once ; but MUST NOT occur more than once.
; ;
class / completed / created / description / class / completed / created / description /
dtstart / geo / last-mod / location / organizer / dtstart / geo / last-mod / location / organizer /
percent / priority / recurid / seq / status / percent / priority / recurid / seq / status /
summary / url / summary / url /
; ;
; the following is OPTIONAL, ; The following is OPTIONAL,
; but SHOULD NOT occur more than once ; but SHOULD NOT occur more than once.
; ;
rrule / rrule /
; ;
; either 'due' or 'duration' MAY appear in ; Either 'due' or 'duration' MAY appear in
; a 'todoprop', but 'due' and 'duration' ; a 'todoprop', but 'due' and 'duration'
; MUST NOT occur in the same 'todoprop'. ; MUST NOT occur in the same 'todoprop'.
; If 'duration' appear in a 'todoprop', ; If 'duration' appear in a 'todoprop',
; then 'dtstart' MUST also appear in ; then 'dtstart' MUST also appear in
; the same 'todoprop'. ; the same 'todoprop'.
; ;
due / duration / due / duration /
; ;
; the following are OPTIONAL, ; The following are OPTIONAL,
; and MAY occur more than once ; and MAY occur more than once.
; ;
attach / attendee / categories / comment / contact / attach / attendee / categories / comment / contact /
exdate / rstatus / related / resources / exdate / rstatus / related / resources /
rdate / x-prop / iana-prop rdate / x-prop / iana-prop
; ;
) )
Description: A "VTODO" calendar component is a grouping of component Description: A "VTODO" calendar component is a grouping of component
properties and possibly "VALARM" calendar components that properties and possibly "VALARM" calendar components that
represent an action-item or assignment. For example, it can be represent an action-item or assignment. For example, it can be
RFC 5545 iCalendar September 2009
used to represent an item of work assigned to an individual; such used to represent an item of work assigned to an individual; such
as "turn in travel expense today". as "turn in travel expense today".
The "VTODO" calendar component cannot be nested within another The "VTODO" calendar component cannot be nested within another
calendar component. However, "VTODO" calendar components can be calendar component. However, "VTODO" calendar components can be
related to each other or to a "VEVENT" or to a "VJOURNAL" calendar related to each other or to a "VEVENT" or to a "VJOURNAL" calendar
component with the "RELATED-TO" property. component with the "RELATED-TO" property.
A "VTODO" calendar component without the "DTSTART" and "DUE" (or A "VTODO" calendar component without the "DTSTART" and "DUE" (or
"DURATION") properties specifies a to-do that will be associated "DURATION") properties specifies a to-do that will be associated
with each successive calendar date, until it is completed. with each successive calendar date, until it is completed.
Examples: The following is an example of a "VTODO" calendar Examples: The following is an example of a "VTODO" calendar
component that needs to be completed before May 1st, 2007. On component that needs to be completed before May 1st, 2007. On
midnight May 1st, 2007 this to-do would be considered overdue. midnight May 1st, 2007 this to-do would be considered overdue.
BEGIN:VTODO BEGIN:VTODO
UID:20070313T123432Z-456553@example.com UID:20070313T123432Z-456553@example.com
DTSTAMP:20070313T123432Z DTSTAMP:20070313T123432Z
DUE;VALUE=DATE:20070501 DUE;VALUE=DATE:20070501
SUMMARY:Submit Quebec Income Tax Return for 2006 SUMMARY:Submit Quebec Income Tax Return for 2006
CLASS:CONFIDENTIAL CLASS:CONFIDENTIAL
CATEGORIES:FAMILY,FINANCE CATEGORIES:FAMILY,FINANCE
STATUS:NEEDS-ACTION STATUS:NEEDS-ACTION
END:VTODO END:VTODO
The following is an example of a "VTODO" calendar component that The following is an example of a "VTODO" calendar component that
was due before 1:00 P.M. UTC on July 9th, 2007 and was completed was due before 1:00 P.M. UTC on July 9th, 2007 and was completed
on July 7th, 2007 at 10:00 A.M. UTC. on July 7th, 2007 at 10:00 A.M. UTC.
BEGIN:VTODO BEGIN:VTODO
UID:20070514T103211Z-123404@example.com UID:20070514T103211Z-123404@example.com
DTSTAMP:20070514T103211Z DTSTAMP:20070514T103211Z
DTSTART:20070514T110000Z DTSTART:20070514T110000Z
DUE:20070709T130000Z DUE:20070709T130000Z
COMPLETED:20070707T100000Z COMPLETED:20070707T100000Z
SUMMARY:Submit Revised Internet-Draft SUMMARY:Submit Revised Internet-Draft
PRIORITY:1 PRIORITY:1
STATUS:NEEDS-ACTION STATUS:NEEDS-ACTION
END:VTODO END:VTODO
3.6.3. Journal Component 3.6.3. Journal Component
Component Name: VJOURNAL Component Name: VJOURNAL
Purpose: Provide a grouping of component properties that describe a Purpose: Provide a grouping of component properties that describe a
journal entry. journal entry.
RFC 5545 iCalendar September 2009
Format Definition: A "VJOURNAL" calendar component is defined by the Format Definition: A "VJOURNAL" calendar component is defined by the
following notation: following notation:
journalc = "BEGIN" ":" "VJOURNAL" CRLF journalc = "BEGIN" ":" "VJOURNAL" CRLF
jourprop jourprop
"END" ":" "VJOURNAL" CRLF "END" ":" "VJOURNAL" CRLF
jourprop = *( jourprop = *(
; ;
; the following are REQUIRED, ; The following are REQUIRED,
; but MUST NOT occur more than once ; but MUST NOT occur more than once.
; ;
dtstamp / uid / dtstamp / uid /
; ;
; the following are OPTIONAL, ; The following are OPTIONAL,
; but MUST NOT occur more than once ; but MUST NOT occur more than once.
; ;
class / created / dtstart / class / created / dtstart /
last-mod / organizer / recurid / seq / last-mod / organizer / recurid / seq /
status / summary / url / status / summary / url /
; ;
; the following is OPTIONAL, ; The following is OPTIONAL,
; but SHOULD NOT occur more than once ; but SHOULD NOT occur more than once.
; ;
rrule / rrule /
; ;
; the following are OPTIONAL, ; The following are OPTIONAL,
; and MAY occur more than once ; and MAY occur more than once.
; ;
attach / attendee / categories / comment / attach / attendee / categories / comment /
contact / description / exdate / related / rdate / contact / description / exdate / related / rdate /
rstatus / x-prop / iana-prop rstatus / x-prop / iana-prop
; ;
) )
Description: A "VJOURNAL" calendar component is a grouping of Description: A "VJOURNAL" calendar component is a grouping of
component properties that represent one or more descriptive text component properties that represent one or more descriptive text
notes associated with a particular calendar date. The "DTSTART" notes associated with a particular calendar date. The "DTSTART"
property is used to specify the calendar date that the journal property is used to specify the calendar date with which the
entry is associated with. Generally, it will have a DATE value journal entry is associated. Generally, it will have a DATE value
data type, but it can also be used to specify a DATE-TIME value data type, but it can also be used to specify a DATE-TIME value
data type. Examples of a journal entry include a daily record of data type. Examples of a journal entry include a daily record of
a legislative body or a journal entry of individual telephone a legislative body or a journal entry of individual telephone
contacts for the day or an ordered list of accomplishments for the contacts for the day or an ordered list of accomplishments for the
day. The "VJOURNAL" calendar component can also be used to day. The "VJOURNAL" calendar component can also be used to
associate a document with a calendar date. associate a document with a calendar date.
RFC 5545 iCalendar September 2009
The "VJOURNAL" calendar component does not take up time on a The "VJOURNAL" calendar component does not take up time on a
calendar. Hence, it does not play a role in free or busy time calendar. Hence, it does not play a role in free or busy time
searches -- it is as though it has a time transparency value of searches -- it is as though it has a time transparency value of
TRANSPARENT. It is transparent to any such searches. TRANSPARENT. It is transparent to any such searches.
The "VJOURNAL" calendar component cannot be nested within another The "VJOURNAL" calendar component cannot be nested within another
calendar component. However, "VJOURNAL" calendar components can calendar component. However, "VJOURNAL" calendar components can
be related to each other or to a "VEVENT" or to a "VTODO" calendar be related to each other or to a "VEVENT" or to a "VTODO" calendar
component, with the "RELATED-TO" property. component, with the "RELATED-TO" property.
Example: The following is an example of the "VJOURNAL" calendar Example: The following is an example of the "VJOURNAL" calendar
component: component:
BEGIN:VJOURNAL BEGIN:VJOURNAL
UID:19970901T130000Z-123405@example.com UID:19970901T130000Z-123405@example.com
DTSTAMP:19970901T130000Z DTSTAMP:19970901T130000Z
DTSTART;VALUE=DATE:19970317 DTSTART;VALUE=DATE:19970317
SUMMARY:Staff meeting minutes SUMMARY:Staff meeting minutes
DESCRIPTION:1. Staff meeting: Participants include Joe\, Lisa DESCRIPTION:1. Staff meeting: Participants include Joe\,
and Bob. Aurora project plans were reviewed. There is currentl Lisa\, and Bob. Aurora project plans were reviewed.
y no budget reserves for this project. Lisa will escalate to There is currently no budget reserves for this project.
management. Next meeting on Tuesday.\n Lisa will escalate to management. Next meeting on Tuesday.\n
2. Telephone Conference: ABC Corp. sales representative called 2. Telephone Conference: ABC Corp. sales representative
to discuss new printer. Promised to get us a demo by Friday.\n called to discuss new printer. Promised to get us a demo by
3. Henry Miller (Handsoff Insurance): Car was totaled by tree. Friday.\n3. Henry Miller (Handsoff Insurance): Car was
Is looking into a loaner car. 555-2323 (tel). totaled by tree. Is looking into a loaner car. 555-2323
END:VJOURNAL (tel).
END:VJOURNAL
3.6.4. Free/Busy Component 3.6.4. Free/Busy Component
Component Name: VFREEBUSY Component Name: VFREEBUSY
Purpose: Provide a grouping of component properties that describe Purpose: Provide a grouping of component properties that describe
either a request for free/busy time, describe a response to a either a request for free/busy time, describe a response to a
request for free/busy time or describe a published set of busy request for free/busy time, or describe a published set of busy
time. time.
Format Definition: A "VFREEBUSY" calendar component is defined by Format Definition: A "VFREEBUSY" calendar component is defined by
the following notation: the following notation:
freebusyc = "BEGIN" ":" "VFREEBUSY" CRLF freebusyc = "BEGIN" ":" "VFREEBUSY" CRLF
fbprop fbprop
"END" ":" "VFREEBUSY" CRLF "END" ":" "VFREEBUSY" CRLF
fbprop = *( fbprop = *(
; ;
; the following are REQUIRED, ; The following are REQUIRED,
; but MUST NOT occur more than once
; RFC 5545 iCalendar September 2009
dtstamp / uid /
; ; but MUST NOT occur more than once.
; the following are OPTIONAL, ;
; but MUST NOT occur more than once dtstamp / uid /
; ;
contact / dtstart / dtend / ; The following are OPTIONAL,
organizer / url / ; but MUST NOT occur more than once.
; ;
; the following are OPTIONAL, contact / dtstart / dtend /
; and MAY occur more than once organizer / url /
; ;
attendee / comment / freebusy / rstatus / x-prop / ; The following are OPTIONAL,
iana-prop ; and MAY occur more than once.
; ;
) attendee / comment / freebusy / rstatus / x-prop /
iana-prop
;
)
Description: A "VFREEBUSY" calendar component is a grouping of Description: A "VFREEBUSY" calendar component is a grouping of
component properties that represents either a request for, a reply component properties that represents either a request for free or
to a request for free or busy time information or a published set busy time information, a reply to a request for free or busy time
of busy time information. information, or a published set of busy time information.
When used to request free/busy time information, the "ATTENDEE" When used to request free/busy time information, the "ATTENDEE"
property specifies the calendar users whose free/busy time is property specifies the calendar users whose free/busy time is
being requested; the "ORGANIZER" property specifies the calendar being requested; the "ORGANIZER" property specifies the calendar
user who is requesting the free/busy time; the "DTSTART" and user who is requesting the free/busy time; the "DTSTART" and
"DTEND" properties specify the window of time for which the free/ "DTEND" properties specify the window of time for which the free/
busy time is being requested; the "UID" and "DTSTAMP" properties busy time is being requested; the "UID" and "DTSTAMP" properties
are specified to assist in proper sequencing of multiple free/busy are specified to assist in proper sequencing of multiple free/busy
time requests. time requests.
skipping to change at page 66, line 10 skipping to change at page 60, line 52
that originally requested the free/busy time; the "FREEBUSY" that originally requested the free/busy time; the "FREEBUSY"
property specifies the free/busy time information (if it exists); property specifies the free/busy time information (if it exists);
and the "UID" and "DTSTAMP" properties are specified to assist in and the "UID" and "DTSTAMP" properties are specified to assist in
proper sequencing of multiple free/busy time replies. proper sequencing of multiple free/busy time replies.
When used to publish busy time, the "ORGANIZER" property specifies When used to publish busy time, the "ORGANIZER" property specifies
the calendar user associated with the published busy time; the the calendar user associated with the published busy time; the
"DTSTART" and "DTEND" properties specify an inclusive time window "DTSTART" and "DTEND" properties specify an inclusive time window
that surrounds the busy time information; the "FREEBUSY" property that surrounds the busy time information; the "FREEBUSY" property
specifies the published busy time information; and the "DTSTAMP" specifies the published busy time information; and the "DTSTAMP"
property specifies the date/time that iCalendar object was property specifies the DATE-TIME that iCalendar object was
created. created.
RFC 5545 iCalendar September 2009
The "VFREEBUSY" calendar component cannot be nested within another The "VFREEBUSY" calendar component cannot be nested within another
calendar component. Multiple "VFREEBUSY" calendar components can calendar component. Multiple "VFREEBUSY" calendar components can
be specified within an iCalendar object. This permits the be specified within an iCalendar object. This permits the
grouping of Free/Busy information into logical collections, such grouping of free/busy information into logical collections, such
as monthly groups of busy time information. as monthly groups of busy time information.
The "VFREEBUSY" calendar component is intended for use in The "VFREEBUSY" calendar component is intended for use in
iCalendar object methods involving requests for free time, iCalendar object methods involving requests for free time,
requests for busy time, requests for both free and busy, and the requests for busy time, requests for both free and busy, and the
associated replies. associated replies.
Free/Busy information is represented with the "FREEBUSY" property. Free/Busy information is represented with the "FREEBUSY" property.
This property provides a terse representation of time periods. This property provides a terse representation of time periods.
One or more "FREEBUSY" properties can be specified in the One or more "FREEBUSY" properties can be specified in the
skipping to change at page 66, line 41 skipping to change at page 61, line 35
properties. properties.
The recurrence properties ("RRULE", "RDATE", "EXDATE") are not The recurrence properties ("RRULE", "RDATE", "EXDATE") are not
permitted within a "VFREEBUSY" calendar component. Any recurring permitted within a "VFREEBUSY" calendar component. Any recurring
events are resolved into their individual busy time periods using events are resolved into their individual busy time periods using
the "FREEBUSY" property. the "FREEBUSY" property.
Example: The following is an example of a "VFREEBUSY" calendar Example: The following is an example of a "VFREEBUSY" calendar
component used to request free or busy time information: component used to request free or busy time information:
BEGIN:VFREEBUSY BEGIN:VFREEBUSY
UID:19970901T082949Z-FA43EF@example.com UID:19970901T082949Z-FA43EF@example.com
ORGANIZER:mailto:jane_doe@example.com ORGANIZER:mailto:jane_doe@example.com
ATTENDEE:mailto:john_public@example.com ATTENDEE:mailto:john_public@example.com
DTSTART:19971015T050000Z DTSTART:19971015T050000Z
DTEND:19971016T050000Z DTEND:19971016T050000Z
DTSTAMP:19970901T083000Z DTSTAMP:19970901T083000Z
END:VFREEBUSY END:VFREEBUSY
RFC 5545 iCalendar September 2009
The following is an example of a "VFREEBUSY" calendar component The following is an example of a "VFREEBUSY" calendar component
used to reply to the request with busy time information: used to reply to the request with busy time information:
BEGIN:VFREEBUSY BEGIN:VFREEBUSY
UID:19970901T095957Z-76A912@example.com UID:19970901T095957Z-76A912@example.com
ORGANIZER:mailto:jane_doe@example.com ORGANIZER:mailto:jane_doe@example.com
ATTENDEE:mailto:john_public@example.com ATTENDEE:mailto:john_public@example.com
DTSTAMP:19970901T100000Z DTSTAMP:19970901T100000Z
FREEBUSY:19971015T050000Z/PT8H30M, FREEBUSY:19971015T050000Z/PT8H30M,
19971015T160000Z/PT5H30M,19971015T223000Z/PT6H30M 19971015T160000Z/PT5H30M,19971015T223000Z/PT6H30M
URL:http://example.com/pub/busy/jpublic-01.ifb URL:http://example.com/pub/busy/jpublic-01.ifb
COMMENT:This iCalendar file contains busy time information for COMMENT:This iCalendar file contains busy time information for
the next three months. the next three months.
END:VFREEBUSY END:VFREEBUSY
The following is an example of a "VFREEBUSY" calendar component The following is an example of a "VFREEBUSY" calendar component
used to publish busy time information. used to publish busy time information:
BEGIN:VFREEBUSY BEGIN:VFREEBUSY
UID:19970901T115957Z-76A912@example.com UID:19970901T115957Z-76A912@example.com
DTSTAMP:19970901T120000Z DTSTAMP:19970901T120000Z
ORGANIZER:jsmith@example.com ORGANIZER:jsmith@example.com
DTSTART:19980313T141711Z DTSTART:19980313T141711Z
DTEND:19980410T141711Z DTEND:19980410T141711Z
FREEBUSY:19980314T233000Z/19980315T003000Z FREEBUSY:19980314T233000Z/19980315T003000Z
FREEBUSY:19980316T153000Z/19980316T163000Z FREEBUSY:19980316T153000Z/19980316T163000Z
FREEBUSY:19980318T030000Z/19980318T040000Z FREEBUSY:19980318T030000Z/19980318T040000Z
URL:http://www.example.com/calendar/busytime/jsmith.ifb URL:http://www.example.com/calendar/busytime/jsmith.ifb
END:VFREEBUSY END:VFREEBUSY
3.6.5. Time Zone Component 3.6.5. Time Zone Component
Component Name: VTIMEZONE Component Name: VTIMEZONE
Purpose: Provide a grouping of component properties that defines a Purpose: Provide a grouping of component properties that defines a
time zone. time zone.
Format Definition: A "VTIMEZONE" calendar component is defined by Format Definition: A "VTIMEZONE" calendar component is defined by
the following notation: the following notation:
timezonec = "BEGIN" ":" "VTIMEZONE" CRLF timezonec = "BEGIN" ":" "VTIMEZONE" CRLF
*( *(
; ;
; 'tzid' is REQUIRED, but MUST NOT occur more ; 'tzid' is REQUIRED, but MUST NOT occur more
; than once ; than once.
; ;
tzid / tzid /
; ;
; 'last-mod' and 'tzurl' are OPTIONAL,
; but MUST NOT occur more than once
;
last-mod / tzurl /
;
; one of 'standardc' or 'daylightc' MUST occur
; and each MAY occur more than once.
;
standardc / daylightc /
;
; the following are OPTIONAL,
; and MAY occur more than once
;
x-prop / iana-prop
;
)
"END" ":" "VTIMEZONE" CRLF
standardc = "BEGIN" ":" "STANDARD" CRLF RFC 5545 iCalendar September 2009
tzprop
"END" ":" "STANDARD" CRLF
daylightc = "BEGIN" ":" "DAYLIGHT" CRLF ; 'last-mod' and 'tzurl' are OPTIONAL,
tzprop ; but MUST NOT occur more than once.
"END" ":" "DAYLIGHT" CRLF ;
last-mod / tzurl /
;
; One of 'standardc' or 'daylightc' MUST occur
; and each MAY occur more than once.
;
standardc / daylightc /
;
; The following are OPTIONAL,
; and MAY occur more than once.
;
x-prop / iana-prop
;
)
"END" ":" "VTIMEZONE" CRLF
tzprop = *( standardc = "BEGIN" ":" "STANDARD" CRLF
; tzprop
; the following are REQUIRED, "END" ":" "STANDARD" CRLF
; but MUST NOT occur more than once
; daylightc = "BEGIN" ":" "DAYLIGHT" CRLF
dtstart / tzoffsetto / tzoffsetfrom / tzprop
; "END" ":" "DAYLIGHT" CRLF
; the following is OPTIONAL,
; but SHOULD NOT occur more than once tzprop = *(
; ;
rrule / ; The following are REQUIRED,
; ; but MUST NOT occur more than once.
; the following are OPTIONAL, ;
; and MAY occur more than once dtstart / tzoffsetto / tzoffsetfrom /
; ;
comment / rdate / tzname / x-prop / iana-prop ; The following is OPTIONAL,
; ; but SHOULD NOT occur more than once.
) ;
rrule /
;
; The following are OPTIONAL,
; and MAY occur more than once.
;
comment / rdate / tzname / x-prop / iana-prop
;
)
Description: A time zone is unambiguously defined by the set of time Description: A time zone is unambiguously defined by the set of time
measurement rules determined by the governing body for a given measurement rules determined by the governing body for a given
geographic area. These rules describe at a minimum the base geographic area. These rules describe, at a minimum, the base
RFC 5545 iCalendar September 2009
offset from UTC for the time zone, often referred to as the offset from UTC for the time zone, often referred to as the
Standard Time offset. Many locations adjust their Standard Time Standard Time offset. Many locations adjust their Standard Time
forward or backward by one hour, in order to accommodate seasonal forward or backward by one hour, in order to accommodate seasonal
changes in number of daylight hours, often referred to as Daylight changes in number of daylight hours, often referred to as Daylight
Saving Time. Some locations adjust their time by a fraction of an Saving Time. Some locations adjust their time by a fraction of an
hour. Standard Time is also known as Winter Time. Daylight hour. Standard Time is also known as Winter Time. Daylight
Saving Time is also known as Advanced Time, Summer Time, or Legal Saving Time is also known as Advanced Time, Summer Time, or Legal
Time in certain countries. The following table shows the changes Time in certain countries. The following table shows the changes
in time zone rules in effect for New York City starting from 1967. in time zone rules in effect for New York City starting from 1967.
Each line represents a description or rule for a particular Each line represents a description or rule for a particular
observance. observance.
Effective Observance Rule Effective Observance Rule
+-----------+--------------------------+--------+--------------+ +-----------+--------------------------+--------+--------------+
| Date | (Date/Time) | Offset | Abbreviation | | Date | (Date-Time) | Offset | Abbreviation |
+-----------+--------------------------+--------+--------------+ +-----------+--------------------------+--------+--------------+
| 1967-1973 | last Sun in Apr, 02:00 | -0400 | EDT | | 1967-1973 | last Sun in Apr, 02:00 | -0400 | EDT |
| | | | | | | | | |
| 1967-2006 | last Sun in Oct, 02:00 | -0500 | EST | | 1967-2006 | last Sun in Oct, 02:00 | -0500 | EST |
| | | | | | | | | |
| 1974-1974 | Jan 6, 02:00 | -0400 | EDT | | 1974-1974 | Jan 6, 02:00 | -0400 | EDT |
| | | | | | | | | |
| 1975-1975 | Feb 23, 02:00 | -0400 | EDT | | 1975-1975 | Feb 23, 02:00 | -0400 | EDT |
| | | | | | | | | |
| 1976-1986 | last Sun in Apr, 02:00 | -0400 | EDT | | 1976-1986 | last Sun in Apr, 02:00 | -0400 | EDT |
| | | | | | | | | |
| 1987-2006 | first Sun in Apr, 02:00 | -0400 | EDT | | 1987-2006 | first Sun in Apr, 02:00 | -0400 | EDT |
| | | | | | | | | |
| 2007-* | second Sun in Mar, 02:00 | -0400 | EDT | | 2007-* | second Sun in Mar, 02:00 | -0400 | EDT |
| | | | | | | | | |
| 2007-* | first Sun in Nov, 02:00 | -0500 | EST | | 2007-* | first Sun in Nov, 02:00 | -0500 | EST |
+-----------+--------------------------+--------+--------------+ +-----------+--------------------------+--------+--------------+
Note: The specification of a global time zone registry is not Note: The specification of a global time zone registry is not
addressed by this document and is left for future study. addressed by this document and is left for future study.
However, implementers may find the TZ database [TZDB] a useful However, implementers may find the TZ database [TZDB] a useful
reference. It is an informal, public-domain collection of time reference. It is an informal, public-domain collection of time
zone information, which is currently being maintained by zone information, which is currently being maintained by
volunteer Internet participants, and is used in several volunteer Internet participants, and is used in several
operating systems. This database contains current and operating systems. This database contains current and
historical time zone information for a wide variety of historical time zone information for a wide variety of
locations around the globe; it provides a time zone identifier locations around the globe; it provides a time zone identifier
for every unique time zone rule set in actual use since 1970, for every unique time zone rule set in actual use since 1970,
with historical data going back to the introduction of standard with historical data going back to the introduction of standard
time. time.
RFC 5545 iCalendar September 2009
Interoperability between two calendaring and scheduling Interoperability between two calendaring and scheduling
applications, especially for recurring events, to-dos or journal applications, especially for recurring events, to-dos or journal
entries, is dependent on the ability to capture and convey date entries, is dependent on the ability to capture and convey date
and time information in an unambiguous format. The specification and time information in an unambiguous format. The specification
of current time zone information is integral to this behavior. of current time zone information is integral to this behavior.
If present, the "VTIMEZONE" calendar component defines the set of If present, the "VTIMEZONE" calendar component defines the set of
Standard Time and Daylight Saving Time observances (or rules) for Standard Time and Daylight Saving Time observances (or rules) for
a particular time zone for a given interval of time. The a particular time zone for a given interval of time. The
"VTIMEZONE" calendar component cannot be nested within other "VTIMEZONE" calendar component cannot be nested within other
calendar components. Multiple "VTIMEZONE" calendar components can calendar components. Multiple "VTIMEZONE" calendar components can
exist in an iCalendar object. In this situation, each "VTIMEZONE" exist in an iCalendar object. In this situation, each "VTIMEZONE"
MUST represent a unique time zone definition. This is necessary MUST represent a unique time zone definition. This is necessary
for some classes of events, such as airline flights, that start in for some classes of events, such as airline flights, that start in
one time zone and end in another. one time zone and end in another.
The "VTIMEZONE" calendar component MUST include the "TZID" The "VTIMEZONE" calendar component MUST include the "TZID"
property and at least one definition of a "STANDARD" or "DAYLIGHT" property and at least one definition of a "STANDARD" or "DAYLIGHT"
sub-component. The "STANDARD" or "DAYLIGHT" subcomponent MUST sub-component. The "STANDARD" or "DAYLIGHT" sub-component MUST
include the "DTSTART", "TZOFFSETFROM" and "TZOFFSETTO" properties. include the "DTSTART", "TZOFFSETFROM", and "TZOFFSETTO"
properties.
An individual "VTIMEZONE" calendar component MUST be specified for An individual "VTIMEZONE" calendar component MUST be specified for
each unique "TZID" parameter value specified in the iCalendar each unique "TZID" parameter value specified in the iCalendar
object. In addition, a "VTIMEZONE" calendar component, referred object. In addition, a "VTIMEZONE" calendar component, referred
to by a recurring calendar component, MUST provide valid time zone to by a recurring calendar component, MUST provide valid time zone
information for all recurrence instances. information for all recurrence instances.
Each "VTIMEZONE" calendar component consists of a collection of Each "VTIMEZONE" calendar component consists of a collection of
one or more sub-components that describe the rule for a particular one or more sub-components that describe the rule for a particular
observance (either a Standard Time or a Daylight Saving Time observance (either a Standard Time or a Daylight Saving Time
observance). The "STANDARD" sub-component consists of a observance). The "STANDARD" sub-component consists of a
collection of properties that describe Standard Time. The collection of properties that describe Standard Time. The
"DAYLIGHT" sub-component consists of a collection of properties "DAYLIGHT" sub-component consists of a collection of properties
that describe Daylight Saving Time. In general this collection of that describe Daylight Saving Time. In general, this collection
properties consists of: of properties consists of:
* the first onset date-time for the observance; * the first onset DATE-TIME for the observance;
* the last onset date-time for the observance, if a last onset is * the last onset DATE-TIME for the observance, if a last onset is
known; known;
* the offset to be applied for the observance; * the offset to be applied for the observance;
* a rule that describes the day and time when the observance * a rule that describes the day and time when the observance
takes effect; takes effect;
* an optional name for the observance. * an optional name for the observance.
RFC 5545 iCalendar September 2009
For a given time zone, there may be multiple unique definitions of For a given time zone, there may be multiple unique definitions of
the observances over a period of time. Each observance is the observances over a period of time. Each observance is
described using either a "STANDARD" or "DAYLIGHT" sub-component. described using either a "STANDARD" or "DAYLIGHT" sub-component.
The collection of these sub-components is used to describe the The collection of these sub-components is used to describe the
time zone for a given period of time. The offset to apply at any time zone for a given period of time. The offset to apply at any
given time is found by locating the observance that has the last given time is found by locating the observance that has the last
onset date and time before the time in question, and using the onset date and time before the time in question, and using the
offset value from that observance. offset value from that observance.
The top-level properties in a "VTIMEZONE" calendar component are: The top-level properties in a "VTIMEZONE" calendar component are:
skipping to change at page 71, line 32 skipping to change at page 66, line 30
an iCalendar object. an iCalendar object.
The optional "LAST-MODIFIED" property is a UTC value that The optional "LAST-MODIFIED" property is a UTC value that
specifies the date and time that this time zone definition was specifies the date and time that this time zone definition was
last updated. last updated.
The optional "TZURL" property is a url value that points to a The optional "TZURL" property is a url value that points to a
published "VTIMEZONE" definition. "TZURL" SHOULD refer to a published "VTIMEZONE" definition. "TZURL" SHOULD refer to a
resource that is accessible by anyone who might need to interpret resource that is accessible by anyone who might need to interpret
the object. This SHOULD NOT normally be a "file" URL or other URL the object. This SHOULD NOT normally be a "file" URL or other URL
that is not widely-accessible. that is not widely accessible.
The collection of properties that are used to define the The collection of properties that are used to define the
"STANDARD" and "DAYLIGHT" sub-components include: "STANDARD" and "DAYLIGHT" sub-components include:
The mandatory "DTSTART" property gives the effective onset date The mandatory "DTSTART" property gives the effective onset date
and local time for the time zone sub-component definition. and local time for the time zone sub-component definition.
"DTSTART" in this usage MUST be specified as a date with local "DTSTART" in this usage MUST be specified as a date with a local
time value. time value.
The mandatory "TZOFFSETFROM" property gives the UTC offset which The mandatory "TZOFFSETFROM" property gives the UTC offset that is
is in use when the onset of this time zone observance begins. in use when the onset of this time zone observance begins.
"TZOFFSETFROM" is combined with "DTSTART" to define the effective "TZOFFSETFROM" is combined with "DTSTART" to define the effective
onset for the time zone sub-component definition. For example, onset for the time zone sub-component definition. For example,
the following represents the time at which the observance of the following represents the time at which the observance of
Standard Time took effect in Fall 1967 for New York City: Standard Time took effect in Fall 1967 for New York City:
DTSTART:19671029T020000 DTSTART:19671029T020000
TZOFFSETFROM:-0400 TZOFFSETFROM:-0400
The mandatory "TZOFFSETTO" property gives the UTC offset for the The mandatory "TZOFFSETTO" property gives the UTC offset for the
time zone sub-component (Standard Time or Daylight Saving Time) time zone sub-component (Standard Time or Daylight Saving Time)
when this observance is in use. when this observance is in use.
RFC 5545 iCalendar September 2009
The optional "TZNAME" property is the customary name for the time The optional "TZNAME" property is the customary name for the time
zone. This could be used for displaying dates. zone. This could be used for displaying dates.
The onset date-times for the observance defined by the time zone The onset DATE-TIME values for the observance defined by the time
sub-component is defined by the "DTSTART", "RRULE", and "RDATE" zone sub-component is defined by the "DTSTART", "RRULE", and
properties. "RDATE" properties.
The "RRULE" property defines the recurrence rule for the onset of The "RRULE" property defines the recurrence rule for the onset of
the observance defined by this time zone sub-component. Some the observance defined by this time zone sub-component. Some
specific requirements for the usage of "RRULE" for this purpose specific requirements for the usage of "RRULE" for this purpose
include: include:
* If observance is known to have an effective end date, the * If observance is known to have an effective end date, the
"UNTIL" recurrence rule parameter MUST be used to specify the "UNTIL" recurrence rule parameter MUST be used to specify the
last valid onset of this observance (i.e., the UNTIL date-time last valid onset of this observance (i.e., the UNTIL DATE-TIME
will be equal to the last instance generated by the recurrence will be equal to the last instance generated by the recurrence
pattern). It MUST be specified in UTC time. pattern). It MUST be specified in UTC time.
* The "DTSTART" and the "TZOFFSETFROM" properties MUST be used * The "DTSTART" and the "TZOFFSETFROM" properties MUST be used
when generating the onset date-time values (instances) from the when generating the onset DATE-TIME values (instances) from the
"RRULE". "RRULE".
The "RDATE" property can also be used to define the onset of the The "RDATE" property can also be used to define the onset of the
observance by giving the individual onset date and times. "RDATE" observance by giving the individual onset date and times. "RDATE"
in this usage MUST be specified as a date with local time value, in this usage MUST be specified as a date with local time value,
relative to the UTC offset specified in the "TZOFFSETFROM" relative to the UTC offset specified in the "TZOFFSETFROM"
property. property.
The optional "COMMENT" property is also allowed for descriptive The optional "COMMENT" property is also allowed for descriptive
explanatory text. explanatory text.
Example: The following are examples of the "VTIMEZONE" calendar Example: The following are examples of the "VTIMEZONE" calendar
component: component:
This is an example showing all the time zone rules for New York This is an example showing all the time zone rules for New York
City since April 30, 1967 at 03:00:00 EDT. City since April 30, 1967 at 03:00:00 EDT.
BEGIN:VTIMEZONE BEGIN:VTIMEZONE
TZID:America/New_York TZID:America/New_York
LAST-MODIFIED:20050809T050000Z LAST-MODIFIED:20050809T050000Z
BEGIN:DAYLIGHT BEGIN:DAYLIGHT
DTSTART:19670430T020000 DTSTART:19670430T020000
RRULE:FREQ=YEARLY;BYMONTH=4;BYDAY=-1SU;UNTIL=19730429T070000Z RRULE:FREQ=YEARLY;BYMONTH=4;BYDAY=-1SU;UNTIL=19730429T070000Z
TZOFFSETFROM:-0500 TZOFFSETFROM:-0500
TZOFFSETTO:-0400 TZOFFSETTO:-0400
TZNAME:EDT TZNAME:EDT
END:DAYLIGHT END:DAYLIGHT
BEGIN:STANDARD BEGIN:STANDARD
DTSTART:19671029T020000
RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU;UNTIL=20061029T060000Z RFC 5545 iCalendar September 2009
TZOFFSETFROM:-0400
TZOFFSETTO:-0500 DTSTART:19671029T020000
TZNAME:EST RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU;UNTIL=20061029T060000Z
END:STANDARD TZOFFSETFROM:-0400
BEGIN:DAYLIGHT TZOFFSETTO:-0500
DTSTART:19740106T020000 TZNAME:EST
RDATE:19750223T020000 END:STANDARD
TZOFFSETFROM:-0500 BEGIN:DAYLIGHT
TZOFFSETTO:-0400 DTSTART:19740106T020000
TZNAME:EDT RDATE:19750223T020000
END:DAYLIGHT TZOFFSETFROM:-0500
BEGIN:DAYLIGHT TZOFFSETTO:-0400
DTSTART:19760425T020000 TZNAME:EDT
RRULE:FREQ=YEARLY;BYMONTH=4;BYDAY=-1SU;UNTIL=19860427T070000Z END:DAYLIGHT
TZOFFSETFROM:-0500 BEGIN:DAYLIGHT
TZOFFSETTO:-0400 DTSTART:19760425T020000
TZNAME:EDT RRULE:FREQ=YEARLY;BYMONTH=4;BYDAY=-1SU;UNTIL=19860427T070000Z
END:DAYLIGHT TZOFFSETFROM:-0500
BEGIN:DAYLIGHT TZOFFSETTO:-0400
DTSTART:19870405T020000 TZNAME:EDT
RRULE:FREQ=YEARLY;BYMONTH=4;BYDAY=1SU;UNTIL=20060402T070000Z END:DAYLIGHT
TZOFFSETFROM:-0500 BEGIN:DAYLIGHT
TZOFFSETTO:-0400 DTSTART:19870405T020000
TZNAME:EDT RRULE:FREQ=YEARLY;BYMONTH=4;BYDAY=1SU;UNTIL=20060402T070000Z
END:DAYLIGHT TZOFFSETFROM:-0500
BEGIN:DAYLIGHT TZOFFSETTO:-0400
DTSTART:20070311T020000 TZNAME:EDT
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU END:DAYLIGHT
TZOFFSETFROM:-0500 BEGIN:DAYLIGHT
TZOFFSETTO:-0400 DTSTART:20070311T020000
TZNAME:EDT RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU
END:DAYLIGHT TZOFFSETFROM:-0500
BEGIN:STANDARD TZOFFSETTO:-0400
DTSTART:20071104T020000 TZNAME:EDT
RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU END:DAYLIGHT
TZOFFSETFROM:-0400 BEGIN:STANDARD
TZOFFSETTO:-0500 DTSTART:20071104T020000
TZNAME:EST RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU
END:STANDARD TZOFFSETFROM:-0400
END:VTIMEZONE TZOFFSETTO:-0500
TZNAME:EST
END:STANDARD
END:VTIMEZONE
This is an example showing time zone information for New York City This is an example showing time zone information for New York City
using only the "DTSTART" property. Note that this is only using only the "DTSTART" property. Note that this is only
suitable for a recurring event that starts on or later than March suitable for a recurring event that starts on or later than March
11, 2007 at 03:00:00 EDT (i.e., the earliest effective transition 11, 2007 at 03:00:00 EDT (i.e., the earliest effective transition
date and time) and ends no later than March 9, 2008 at 01:59:59 date and time) and ends no later than March 9, 2008 at 01:59:59
RFC 5545 iCalendar September 2009
EST (i.e., latest valid date and time for EST in this scenario). EST (i.e., latest valid date and time for EST in this scenario).
For example, this can be used for a recurring event that occurs For example, this can be used for a recurring event that occurs
every Friday, 8:00 A.M.-9:00 A.M., starting June 1, 2007, ending every Friday, 8:00 A.M.-9:00 A.M., starting June 1, 2007, ending
December 31, 2007, December 31, 2007,
BEGIN:VTIMEZONE BEGIN:VTIMEZONE
TZID:America/New_York TZID:America/New_York
LAST-MODIFIED:20050809T050000Z LAST-MODIFIED:20050809T050000Z
BEGIN:STANDARD BEGIN:STANDARD
DTSTART:20071104T020000 DTSTART:20071104T020000
TZOFFSETFROM:-0400 TZOFFSETFROM:-0400
TZOFFSETTO:-0500 TZOFFSETTO:-0500
TZNAME:EST TZNAME:EST
END:STANDARD END:STANDARD
BEGIN:DAYLIGHT BEGIN:DAYLIGHT
DTSTART:20070311T020000 DTSTART:20070311T020000
TZOFFSETFROM:-0500 TZOFFSETFROM:-0500
TZOFFSETTO:-0400 TZOFFSETTO:-0400
TZNAME:EDT TZNAME:EDT
END:DAYLIGHT END:DAYLIGHT
END:VTIMEZONE END:VTIMEZONE
This is a simple example showing the current time zone rules for This is a simple example showing the current time zone rules for
New York City using a "RRULE" recurrence pattern. Note that there New York City using a "RRULE" recurrence pattern. Note that there
is no effective end date to either of the Standard Time or is no effective end date to either of the Standard Time or
Daylight Time rules. This information would be valid for a Daylight Time rules. This information would be valid for a
recurring event starting today and continuing indefinitely. recurring event starting today and continuing indefinitely.
BEGIN:VTIMEZONE BEGIN:VTIMEZONE
TZID:America/New_York TZID:America/New_York
LAST-MODIFIED:20050809T050000Z LAST-MODIFIED:20050809T050000Z
TZURL:http://zones.example.com/tz/America-New_York.ics TZURL:http://zones.example.com/tz/America-New_York.ics
BEGIN:STANDARD BEGIN:STANDARD
DTSTART:20071104T020000 DTSTART:20071104T020000
RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU RRULE:FREQ=YEARLY;BYMONTH=11;BYDAY=1SU
TZOFFSETFROM:-0400 TZOFFSETFROM:-0400
TZOFFSETTO:-0500 TZOFFSETTO:-0500
TZNAME:EST TZNAME:EST
END:STANDARD END:STANDARD
BEGIN:DAYLIGHT BEGIN:DAYLIGHT
DTSTART:20070311T020000 DTSTART:20070311T020000
RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=2SU
TZOFFSETFROM:-0500 TZOFFSETFROM:-0500
TZOFFSETTO:-0400 TZOFFSETTO:-0400
TZNAME:EDT TZNAME:EDT
END:DAYLIGHT END:DAYLIGHT
END:VTIMEZONE END:VTIMEZONE
RFC 5545 iCalendar September 2009
This is an example showing a set of rules for a fictitious time This is an example showing a set of rules for a fictitious time
zone where the Daylight Time rule has an effective end date (i.e., zone where the Daylight Time rule has an effective end date (i.e.,
after that date, Daylight Time is no longer observed). after that date, Daylight Time is no longer observed).
BEGIN:VTIMEZONE BEGIN:VTIMEZONE
TZID:Fictitious TZID:Fictitious
LAST-MODIFIED:19870101T000000Z LAST-MODIFIED:19870101T000000Z
BEGIN:STANDARD BEGIN:STANDARD
DTSTART:19671029T020000 DTSTART:19671029T020000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10 RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZOFFSETFROM:-0400 TZOFFSETFROM:-0400
TZOFFSETTO:-0500 TZOFFSETTO:-0500
TZNAME:EST TZNAME:EST
END:STANDARD END:STANDARD
BEGIN:DAYLIGHT BEGIN:DAYLIGHT
DTSTART:19870405T020000 DTSTART:19870405T020000
RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4;UNTIL=19980404T070000Z RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4;UNTIL=19980404T070000Z
TZOFFSETFROM:-0500 TZOFFSETFROM:-0500
TZOFFSETTO:-0400 TZOFFSETTO:-0400
TZNAME:EDT TZNAME:EDT
END:DAYLIGHT END:DAYLIGHT
END:VTIMEZONE END:VTIMEZONE
RFC 5545 iCalendar September 2009
This is an example showing a set of rules for a fictitious time This is an example showing a set of rules for a fictitious time
zone where the first Daylight Time rule has an effective end date. zone where the first Daylight Time rule has an effective end date.
There is a second Daylight Time rule that picks up where the other There is a second Daylight Time rule that picks up where the other
left off. left off.
BEGIN:VTIMEZONE BEGIN:VTIMEZONE
TZID:Fictitious TZID:Fictitious
LAST-MODIFIED:19870101T000000Z LAST-MODIFIED:19870101T000000Z
BEGIN:STANDARD BEGIN:STANDARD
DTSTART:19671029T020000 DTSTART:19671029T020000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10 RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZOFFSETFROM:-0400 TZOFFSETFROM:-0400
TZOFFSETTO:-0500 TZOFFSETTO:-0500
TZNAME:EST TZNAME:EST
END:STANDARD END:STANDARD
BEGIN:DAYLIGHT BEGIN:DAYLIGHT
DTSTART:19870405T020000 DTSTART:19870405T020000
RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4;UNTIL=19980404T070000Z RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4;UNTIL=19980404T070000Z
TZOFFSETFROM:-0500 TZOFFSETFROM:-0500
TZOFFSETTO:-0400 TZOFFSETTO:-0400
TZNAME:EDT TZNAME:EDT
END:DAYLIGHT END:DAYLIGHT
BEGIN:DAYLIGHT BEGIN:DAYLIGHT
DTSTART:19990424T020000 DTSTART:19990424T020000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=4 RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=4
TZOFFSETFROM:-0500 TZOFFSETFROM:-0500
TZOFFSETTO:-0400 TZOFFSETTO:-0400
TZNAME:EDT TZNAME:EDT
END:DAYLIGHT END:DAYLIGHT
END:VTIMEZONE END:VTIMEZONE
3.6.6. Alarm Component 3.6.6. Alarm Component
Component Name: VALARM Component Name: VALARM
Purpose: Provide a grouping of component properties that define an Purpose: Provide a grouping of component properties that define an
alarm. alarm.
Format Definition: A "VALARM" calendar component is defined by the Format Definition: A "VALARM" calendar component is defined by the
following notation: following notation:
alarmc = "BEGIN" ":" "VALARM" CRLF alarmc = "BEGIN" ":" "VALARM" CRLF
(audioprop / dispprop / emailprop) (audioprop / dispprop / emailprop)
"END" ":" "VALARM" CRLF "END" ":" "VALARM" CRLF
audioprop = *( audioprop = *(
; ;
; 'action' and 'trigger' are both REQUIRED, ; 'action' and 'trigger' are both REQUIRED,
; but MUST NOT occur more than once
;
action / trigger /
;
; 'duration' and 'repeat' are both OPTIONAL,
; and MUST NOT occur more than once each,
; but if one occurs, so MUST the other
;
duration / repeat /
;
; the following is OPTIONAL,
; but MUST NOT occur more than once
;
attach /
;
; the following is OPTIONAL,
; and MAY occur more than once
;
x-prop / iana-prop
;
)
dispprop = *( RFC 5545 iCalendar September 2009
;
; the following are REQUIRED,
; but MUST NOT occur more than once
;
action / description / trigger /
;
; 'duration' and 'repeat' are both OPTIONAL,
; and MUST NOT occur more than once each,
; but if one occurs, so MUST the other
;
duration / repeat /
;
; the following is OPTIONAL,
; and MAY occur more than once
;
x-prop / iana-prop
;
)
emailprop = *( ; but MUST NOT occur more than once.
; ;
; the following are all REQUIRED, action / trigger /
; but MUST NOT occur more than once ;
; ; 'duration' and 'repeat' are both OPTIONAL,
action / description / trigger / summary / ; and MUST NOT occur more than once each;
; ; but if one occurs, so MUST the other.
; the following is REQUIRED, ;
; and MAY occur more than once duration / repeat /
; ;
attendee / ; The following is OPTIONAL,
; ; but MUST NOT occur more than once.
; 'duration' and 'repeat' are both OPTIONAL, ;
; and MUST NOT occur more than once each, attach /
; but if one occurs, so MUST the other ;
; ; The following is OPTIONAL,
duration / repeat / ; and MAY occur more than once.
; ;
; the following are OPTIONAL, x-prop / iana-prop
; and MAY occur more than once ;
; )
attach / x-prop / iana-prop
; dispprop = *(
) ;
; The following are REQUIRED,
; but MUST NOT occur more than once.
;
action / description / trigger /
;
; 'duration' and 'repeat' are both OPTIONAL,
; and MUST NOT occur more than once each;
; but if one occurs, so MUST the other.
;
duration / repeat /
;
; The following is OPTIONAL,
; and MAY occur more than once.
;
x-prop / iana-prop
;
)
emailprop = *(
;
; The following are all REQUIRED,
; but MUST NOT occur more than once.
;
action / description / trigger / summary /
RFC 5545 iCalendar September 2009
;
; The following is REQUIRED,
; and MAY occur more than once.
;
attendee /
;
; 'duration' and 'repeat' are both OPTIONAL,
; and MUST NOT occur more than once each;
; but if one occurs, so MUST the other.
;
duration / repeat /
;
; The following are OPTIONAL,
; and MAY occur more than once.
;
attach / x-prop / iana-prop
;
)
Description: A "VALARM" calendar component is a grouping of Description: A "VALARM" calendar component is a grouping of
component properties that is a reminder or alarm for an event or a component properties that is a reminder or alarm for an event or a
to-do. For example, it may be used to define a reminder for a to-do. For example, it may be used to define a reminder for a
pending event or an overdue to-do. pending event or an overdue to-do.
The "VALARM" calendar component MUST include the "ACTION" and The "VALARM" calendar component MUST include the "ACTION" and
"TRIGGER" properties. The "ACTION" property further constrains "TRIGGER" properties. The "ACTION" property further constrains
the "VALARM" calendar component in the following ways: the "VALARM" calendar component in the following ways:
skipping to change at page 78, line 47 skipping to change at page 74, line 4
a "SUMMARY" property, which contains the text to be used as the a "SUMMARY" property, which contains the text to be used as the
message subject, and one or more "ATTENDEE" properties, which message subject, and one or more "ATTENDEE" properties, which
contain the email address of attendees to receive the message. It contain the email address of attendees to receive the message. It
can also include one or more "ATTACH" properties, which are can also include one or more "ATTACH" properties, which are
intended to be sent as message attachments. When the alarm is intended to be sent as message attachments. When the alarm is
triggered, the email message is sent. triggered, the email message is sent.
The "VALARM" calendar component MUST only appear within either a The "VALARM" calendar component MUST only appear within either a
"VEVENT" or "VTODO" calendar component. "VALARM" calendar "VEVENT" or "VTODO" calendar component. "VALARM" calendar
components cannot be nested. Multiple mutually independent components cannot be nested. Multiple mutually independent
RFC 5545 iCalendar September 2009
"VALARM" calendar components can be specified for a single "VALARM" calendar components can be specified for a single
"VEVENT" or "VTODO" calendar component. "VEVENT" or "VTODO" calendar component.
The "TRIGGER" property specifies when the alarm will be triggered. The "TRIGGER" property specifies when the alarm will be triggered.
The "TRIGGER" property specifies a duration prior to the start of The "TRIGGER" property specifies a duration prior to the start of
an event or a to-do. The "TRIGGER" edge may be explicitly set to an event or a to-do. The "TRIGGER" edge may be explicitly set to
be relative to the "START" or "END" of the event or to-do with the be relative to the "START" or "END" of the event or to-do with the
"RELATED" parameter of the "TRIGGER" property. The "TRIGGER" "RELATED" parameter of the "TRIGGER" property. The "TRIGGER"
property value type can alternatively be set to an absolute property value type can alternatively be set to an absolute
calendar date with UTC time. calendar date with UTC time.
skipping to change at page 79, line 50 skipping to change at page 75, line 4
AUDIO specifies an alarm that causes a sound to be played to alert AUDIO specifies an alarm that causes a sound to be played to alert
the user; DISPLAY specifies an alarm that causes a text message to the user; DISPLAY specifies an alarm that causes a text message to
be displayed to the user; and EMAIL specifies an alarm that causes be displayed to the user; and EMAIL specifies an alarm that causes
an electronic email message to be delivered to one or more email an electronic email message to be delivered to one or more email
addresses. addresses.
In an AUDIO alarm, if the optional "ATTACH" property is included, In an AUDIO alarm, if the optional "ATTACH" property is included,
it MUST specify an audio sound resource. The intention is that it MUST specify an audio sound resource. The intention is that
the sound will be played as the alarm effect. If an "ATTACH" the sound will be played as the alarm effect. If an "ATTACH"
property is specified that does not refer to a sound resource, or property is specified that does not refer to a sound resource, or
RFC 5545 iCalendar September 2009
if the specified sound resource cannot be rendered (because its if the specified sound resource cannot be rendered (because its
format is unsupported, or because it cannot be retrieved), then format is unsupported, or because it cannot be retrieved), then
the CUA or other entity responsible for playing the sound may the CUA or other entity responsible for playing the sound may
choose a fallback action, such as playing a built-in default choose a fallback action, such as playing a built-in default
sound, or playing no sound at all. sound, or playing no sound at all.
In a DISPLAY alarm, the intended alarm effect is for the text In a DISPLAY alarm, the intended alarm effect is for the text
value of the "DESCRIPTION" property to be displayed to the user. value of the "DESCRIPTION" property to be displayed to the user.
In an EMAIL alarm, the intended alarm effect is for an email In an EMAIL alarm, the intended alarm effect is for an email
skipping to change at page 80, line 28 skipping to change at page 75, line 34
Note: Implementations should carefully consider whether they Note: Implementations should carefully consider whether they
accept alarm components from untrusted sources, e.g., when accept alarm components from untrusted sources, e.g., when
importing calendar objects from external sources. One importing calendar objects from external sources. One
reasonable policy is to always ignore alarm components that the reasonable policy is to always ignore alarm components that the
calendar user has not set herself, or at least ask for calendar user has not set herself, or at least ask for
confirmation in such a case. confirmation in such a case.
Example: The following example is for a "VALARM" calendar component Example: The following example is for a "VALARM" calendar component
that specifies an audio alarm that will sound at a precise time that specifies an audio alarm that will sound at a precise time
and repeat 4 more times at 15 minute intervals: and repeat 4 more times at 15-minute intervals:
BEGIN:VALARM BEGIN:VALARM
TRIGGER;VALUE=DATE-TIME:19970317T133000Z TRIGGER;VALUE=DATE-TIME:19970317T133000Z
REPEAT:4 REPEAT:4
DURATION:PT15M DURATION:PT15M
ACTION:AUDIO ACTION:AUDIO
ATTACH;FMTTYPE=audio/basic:ftp://example.com/pub/ ATTACH;FMTTYPE=audio/basic:ftp://example.com/pub/
sounds/bell-01.aud sounds/bell-01.aud
END:VALARM END:VALARM
The following example is for a "VALARM" calendar component that The following example is for a "VALARM" calendar component that
specifies a display alarm that will trigger 30 minutes before the specifies a display alarm that will trigger 30 minutes before the
scheduled start of the event or of the to-do it is associated with scheduled start of the event or of the to-do it is associated with
and will repeat 2 more times at 15 minute intervals: and will repeat 2 more times at 15-minute intervals:
BEGIN:VALARM RFC 5545 iCalendar September 2009
TRIGGER:-PT30M
REPEAT:2 BEGIN:VALARM
DURATION:PT15M TRIGGER:-PT30M
ACTION:DISPLAY REPEAT:2
DESCRIPTION:Breakfast meeting with executive\n DURATION:PT15M
team at 8:30 AM EST. ACTION:DISPLAY
END:VALARM DESCRIPTION:Breakfast meeting with executive\n
team at 8:30 AM EST.
END:VALARM
The following example is for a "VALARM" calendar component that The following example is for a "VALARM" calendar component that
specifies an email alarm that will trigger 2 days before the specifies an email alarm that will trigger 2 days before the
scheduled due date/time of a to-do it is associated with. It does scheduled due DATE-TIME of a to-do with which it is associated.
not repeat. The email has a subject, body and attachment link. It does not repeat. The email has a subject, body, and attachment
link.
BEGIN:VALARM BEGIN:VALARM
TRIGGER;RELATED=END:-P2D TRIGGER;RELATED=END:-P2D
ACTION:EMAIL ACTION:EMAIL
ATTENDEE:mailto:john_doe@example.com ATTENDEE:mailto:john_doe@example.com
SUMMARY:*** REMINDER: SEND AGENDA FOR WEEKLY STAFF MEETING *** SUMMARY:*** REMINDER: SEND AGENDA FOR WEEKLY STAFF MEETING ***
DESCRIPTION:A draft agenda needs to be sent out to the attendees DESCRIPTION:A draft agenda needs to be sent out to the attendees
to the weekly managers meeting (MGR-LIST). Attached is a to the weekly managers meeting (MGR-LIST). Attached is a
pointer the document template for the agenda file. pointer the document template for the agenda file.
ATTACH;FMTTYPE=application/msword:http://example.com/ ATTACH;FMTTYPE=application/msword:http://example.com/
templates/agenda.doc templates/agenda.doc
END:VALARM END:VALARM
3.7. Calendar Properties 3.7. Calendar Properties
The Calendar Properties are attributes that apply to the iCalendar The Calendar Properties are attributes that apply to the iCalendar
object, as a whole. These properties do not appear within a calendar object, as a whole. These properties do not appear within a calendar
component. They SHOULD be specified after the "BEGIN:VCALENDAR" component. They SHOULD be specified after the "BEGIN:VCALENDAR"
delimiter string and prior to any calendar component. delimiter string and prior to any calendar component.
3.7.1. Calendar Scale 3.7.1. Calendar Scale
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calendar information specified in the iCalendar object. calendar information specified in the iCalendar object.
Value Type: TEXT Value Type: TEXT
Property Parameters: IANA and non-standard property parameters can Property Parameters: IANA and non-standard property parameters can
be specified on this property. be specified on this property.
Conformance: This property can be specified once in an iCalendar Conformance: This property can be specified once in an iCalendar
object. The default value is "GREGORIAN". object. The default value is "GREGORIAN".
RFC 5545 iCalendar September 2009
Description: This memo is based on the Gregorian calendar scale. Description: This memo is based on the Gregorian calendar scale.
The Gregorian calendar scale is assumed if this property is not The Gregorian calendar scale is assumed if this property is not
specified in the iCalendar object. It is expected that other specified in the iCalendar object. It is expected that other
calendar scales will be defined in other specifications or by calendar scales will be defined in other specifications or by
future versions of this memo. future versions of this memo.
Format Definition: This property is defined by the following Format Definition: This property is defined by the following
notation: notation:
calscale = "CALSCALE" calparam ":" calvalue CRLF calscale = "CALSCALE" calparam ":" calvalue CRLF
calparam = *(";" other-param) calparam = *(";" other-param)
calvalue = "GREGORIAN" calvalue = "GREGORIAN"
Example: The following is an example of this property: Example: The following is an example of this property:
CALSCALE:GREGORIAN CALSCALE:GREGORIAN
3.7.2. Method 3.7.2. Method
Property Name: METHOD Property Name: METHOD
Purpose: This property defines the iCalendar object method Purpose: This property defines the iCalendar object method
associated with the calendar object. associated with the calendar object.
Value Type: TEXT Value Type: TEXT
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object. object.
Description: When used in a MIME message entity, the value of this Description: When used in a MIME message entity, the value of this
property MUST be the same as the Content-Type "method" parameter property MUST be the same as the Content-Type "method" parameter
value. If either the "METHOD" property or the Content-Type value. If either the "METHOD" property or the Content-Type
"method" parameter is specified, then the other MUST also be "method" parameter is specified, then the other MUST also be
specified. specified.
No methods are defined by this specification. This is the subject No methods are defined by this specification. This is the subject
of other specifications, such as the iCalendar Transport- of other specifications, such as the iCalendar Transport-
independent Interoperability Protocol (iTIP) defined by independent Interoperability Protocol (iTIP) defined by [2446bis].
[I-D.ietf-calsify-2446bis].
If this property is not present in the iCalendar object, then a If this property is not present in the iCalendar object, then a
scheduling transaction MUST NOT be assumed. In such cases, the scheduling transaction MUST NOT be assumed. In such cases, the
iCalendar object is merely being used to transport a snapshot of iCalendar object is merely being used to transport a snapshot of
RFC 5545 iCalendar September 2009
some calendar information; without the intention of conveying a some calendar information; without the intention of conveying a
scheduling semantic. scheduling semantic.
Format Definition: This property is defined by the following Format Definition: This property is defined by the following
notation: notation:
method = "METHOD" metparam ":" metvalue CRLF method = "METHOD" metparam ":" metvalue CRLF
metparam = *(";" other-param) metparam = *(";" other-param)
metvalue = iana-token metvalue = iana-token
Example: The following is a hypothetical example of this property to Example: The following is a hypothetical example of this property to
convey that the iCalendar object is a scheduling request: convey that the iCalendar object is a scheduling request:
METHOD:REQUEST METHOD:REQUEST
3.7.3. Product Identifier 3.7.3. Product Identifier
Property Name: PRODID Property Name: PRODID
Purpose: This property specifies the identifier for the product that Purpose: This property specifies the identifier for the product that
created the iCalendar object. created the iCalendar object.
Value Type: TEXT Value Type: TEXT
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an FPI value, as defined in [ISO.9070.1991]. an FPI value, as defined in [ISO.9070.1991].
This property SHOULD NOT be used to alter the interpretation of an This property SHOULD NOT be used to alter the interpretation of an
iCalendar object beyond the semantics specified in this memo. For iCalendar object beyond the semantics specified in this memo. For
example, it is not to be used to further the understanding of non- example, it is not to be used to further the understanding of non-
standard properties. standard properties.
Format Definition: This property is defined by the following Format Definition: This property is defined by the following
notation: notation:
prodid = "PRODID" pidparam ":" pidvalue CRLF prodid = "PRODID" pidparam ":" pidvalue CRLF
pidparam = *(";" other-param) pidparam = *(";" other-param)
pidvalue = text RFC 5545 iCalendar September 2009
;Any text that describes the product and version
;and that is generally assured of being unique. pidvalue = text
;Any text that describes the product and version
;and that is generally assured of being unique.
Example: The following is an example of this property. It does not Example: The following is an example of this property. It does not
imply that English is the default language. imply that English is the default language.
PRODID:-//ABC Corporation//NONSGML My Product//EN PRODID:-//ABC Corporation//NONSGML My Product//EN
3.7.4. Version 3.7.4. Version
Property Name: VERSION Property Name: VERSION
Purpose: This property specifies the identifier corresponding to the Purpose: This property specifies the identifier corresponding to the
highest version number or the minimum and maximum range of the highest version number or the minimum and maximum range of the
iCalendar specification that is required in order to interpret the iCalendar specification that is required in order to interpret the
iCalendar object. iCalendar object.
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be specified on this property. be specified on this property.
Conformance: This property MUST be specified once in an iCalendar Conformance: This property MUST be specified once in an iCalendar
object. object.
Description: A value of "2.0" corresponds to this memo. Description: A value of "2.0" corresponds to this memo.
Format Definition: This property is defined by the following Format Definition: This property is defined by the following
notation: notation:
version = "VERSION" verparam ":" vervalue CRLF version = "VERSION" verparam ":" vervalue CRLF
verparam = *(";" other-param) verparam = *(";" other-param)
vervalue = "2.0" ;This memo vervalue = "2.0" ;This memo
/ maxver / maxver
/ (minver ";" maxver) / (minver ";" maxver)
minver = <A IANA registered iCalendar version identifier> minver = <A IANA-registered iCalendar version identifier>
;Minimum iCalendar version needed to parse the iCalendar object ;Minimum iCalendar version needed to parse the iCalendar object.
maxver = <A IANA registered iCalendar version identifier> maxver = <A IANA-registered iCalendar version identifier>
;Maximum iCalendar version needed to parse the iCalendar object ;Maximum iCalendar version needed to parse the iCalendar object.
RFC 5545 iCalendar September 2009
Example: The following is an example of this property: Example: The following is an example of this property:
VERSION:2.0 VERSION:2.0
3.8. Component Properties 3.8. Component Properties
The following properties can appear within calendar components, as The following properties can appear within calendar components, as
specified by each component property definition. specified by each component property definition.
3.8.1. Descriptive Component Properties 3.8.1. Descriptive Component Properties
The following properties specify descriptive information about The following properties specify descriptive information about
calendar components. calendar components.
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Property Name: ATTACH Property Name: ATTACH
Purpose: This property provides the capability to associate a Purpose: This property provides the capability to associate a
document object with a calendar component. document object with a calendar component.
Value Type: The default value type for this property is URI. The Value Type: The default value type for this property is URI. The
value type can also be set to BINARY to indicate inline binary value type can also be set to BINARY to indicate inline binary
encoded content information. encoded content information.
Property Parameters: IANA, non-standard, inline encoding and value Property Parameters: IANA, non-standard, inline encoding, and value
data type property parameters can be specified on this property. data type property parameters can be specified on this property.
The format type parameter can be specified on this property and is The format type parameter can be specified on this property and is
RECOMMENDED for inline binary encoded content information. RECOMMENDED for inline binary encoded content information.
Conformance: This property can be specified multiple times in a Conformance: This property can be specified multiple times in a
"VEVENT", "VTODO", "VJOURNAL" or "VALARM" calendar component with "VEVENT", "VTODO", "VJOURNAL", or "VALARM" calendar component with
the exception of AUDIO alarm which only allows this property to the exception of AUDIO alarm that only allows this property to
occur once . occur once.
Description: This property is used in "VEVENT", "VTODO", and Description: This property is used in "VEVENT", "VTODO", and
"VJOURNAL" calendar components to associate a resource (e.g., "VJOURNAL" calendar components to associate a resource (e.g.,
document) with the calendar component. This property is used in document) with the calendar component. This property is used in
"VALARM" calendar components to specify an audio sound resource or "VALARM" calendar components to specify an audio sound resource or
an email message attachment. This property can be specified as a an email message attachment. This property can be specified as a
URI pointing to a resource or as inline binary encoded content. URI pointing to a resource or as inline binary encoded content.
When this property is specified as inline binary encoded content, When this property is specified as inline binary encoded content,
calendar applications MAY attempt to guess the media type of the calendar applications MAY attempt to guess the media type of the
resource via inspection of its content if and only if the media resource via inspection of its content if and only if the media
type of the resource is not given by the "FMTTYPE" parameter. If type of the resource is not given by the "FMTTYPE" parameter. If
the media type remains unknown, calendar applications SHOULD treat the media type remains unknown, calendar applications SHOULD treat
it as type "application/octet-stream". it as type "application/octet-stream".
RFC 5545 iCalendar September 2009
Format Definition: This property is defined by the following Format Definition: This property is defined by the following
notation: notation:
attach = "ATTACH" attachparam ( ":" uri ) / attach = "ATTACH" attachparam ( ":" uri ) /
( (
";" "ENCODING" "=" "BASE64" ";" "ENCODING" "=" "BASE64"
";" "VALUE" "=" "BINARY" ";" "VALUE" "=" "BINARY"
":" binary ":" binary
)
CRLF
attachparam = *(
;
; the following is OPTIONAL for URI value
; and RECOMMENDED for BINARY value,
; and MUST NOT occur more than once
;
(";" fmttypeparam) /
;
; the following is OPTIONAL,
; and MAY occur more than once
;
(";" other-param)
;
) )
CRLF
attachparam = *(
;
; The following is OPTIONAL for a URI value,
; RECOMMENDED for a BINARY value,
; and MUST NOT occur more than once.
;
(";" fmttypeparam) /
;
; The following is OPTIONAL,
; and MAY occur more than once.
;
(";" other-param)
;
)
Example: The following are examples of this property: Example: The following are examples of this property:
ATTACH:CID:jsmith.part3.960817T083000.xyzMail@example.com ATTACH:CID:jsmith.part3.960817T083000.xyzMail@example.com
ATTACH;FMTTYPE=application/postscript:ftp://example.com/pub/ ATTACH;FMTTYPE=application/postscript:ftp://example.com/pub/
reports/r-960812.ps reports/r-960812.ps
3.8.1.2. Categories 3.8.1.2. Categories
Property Name: CATEGORIES Property Name: CATEGORIES
Purpose: This property defines the categories for a calendar Purpose: This property defines the categories for a calendar
component. component.
Value Type: TEXT Value Type: TEXT
Property Parameters: IANA, non-standard, and language property Property Parameters: IANA, non-standard, and language property
parameters can be specified on this property. parameters can be specified on this property.
Conformance: The property can be specified within "VEVENT", "VTODO" Conformance: The property can be specified within "VEVENT", "VTODO",
or "VJOURNAL" calendar components. or "VJOURNAL" calendar components.
RFC 5545 iCalendar September 2009
Description: This property is used to specify categories or subtypes Description: This property is used to specify categories or subtypes
of the calendar component. The categories are useful in searching of the calendar component. The categories are useful in searching
for a calendar component of a particular type and category. for a calendar component of a particular type and category.
Within the "VEVENT", "VTODO" or "VJOURNAL" calendar components, Within the "VEVENT", "VTODO", or "VJOURNAL" calendar components,
more than one category can be specified as a list of categories more than one category can be specified as a COMMA-separated list
separated by the COMMA character (US-ASCII decimal 44). of categories.
Format Definition: This property is defined by the following Format Definition: This property is defined by the following
notation: notation:
categories = "CATEGORIES" catparam ":" text *("," text) categories = "CATEGORIES" catparam ":" text *("," text)
CRLF CRLF
catparam = *( catparam = *(
; ;
; the following is OPTIONAL, ; The following is OPTIONAL,
; but MUST NOT occur more than once ; but MUST NOT occur more than once.
; ;
(";" languageparam ) / (";" languageparam ) /
; ;
; the following is OPTIONAL, ; The following is OPTIONAL,
; and MAY occur more than once ; and MAY occur more than once.
; ;
(";" other-param) (";" other-param)
; ;
) )
Example: The following are examples of this property: Example: The following are examples of this property:
CATEGORIES:APPOINTMENT,EDUCATION CATEGORIES:APPOINTMENT,EDUCATION
CATEGORIES:MEETING CATEGORIES:MEETING
3.8.1.3. Classification 3.8.1.3. Classification
Property Name: CLASS Property Name: CLASS
Purpose: This property defines the access classification for a Purpose: This property defines the access classification for a
calendar component. calendar component.
Value Type: TEXT Value Type: TEXT
Property Parameters: IANA and non-standard property parameters can Property Parameters: IANA and non-standard property parameters can
be specified on this property. be specified on this property.
Conformance: The property can be specified once in a "VEVENT", Conformance: The property can be specified once in a "VEVENT",
"VTODO" or "VJOURNAL" calendar components. "VTODO", or "VJOURNAL" calendar components.
RFC 5545 iCalendar September 2009
Description: An access classification is only one component of the Description: An access classification is only one component of the
general security system within a calendar application. It general security system within a calendar application. It
provides a method of capturing the scope of the access the provides a method of capturing the scope of the access the
calendar owner intends for information within an individual calendar owner intends for information within an individual
calendar entry. The access classification of an individual calendar entry. The access classification of an individual
iCalendar component is useful when measured along with the other iCalendar component is useful when measured along with the other
security components of a calendar system (e.g., calendar user security components of a calendar system (e.g., calendar user
authentication, authorization, access rights, access role, etc.). authentication, authorization, access rights, access role, etc.).
Hence, the semantics of the individual access classifications Hence, the semantics of the individual access classifications
cannot be completely defined by this memo alone. Additionally, cannot be completely defined by this memo alone. Additionally,
due to the "blind" nature of most exchange processes using this due to the "blind" nature of most exchange processes using this
memo, these access classifications cannot serve as an enforcement memo, these access classifications cannot serve as an enforcement
statement for a system receiving an iCalendar object. Rather, statement for a system receiving an iCalendar object. Rather,
they provide a method for capturing the intention of the calendar they provide a method for capturing the intention of the calendar
owner for the access to the calendar component. If not specified owner for the access to the calendar component. If not specified
in a component that allows this property, the default value is in a component that allows this property, the default value is
PUBLIC. Applications MUST treat x-name and iana-token value they PUBLIC. Applications MUST treat x-name and iana-token values they
don't recognized the same way as they would the PRIVATE value. don't recognize the same way as they would the PRIVATE value.
Format Definition: This property is defined by the following Format Definition: This property is defined by the following
notation: notation:
class = "CLASS" classparam ":" classvalue CRLF class = "CLASS" classparam ":" classvalue CRLF
classparam = *(";" other-param) classparam = *(";" other-param)
classvalue = "PUBLIC" / "PRIVATE" / "CONFIDENTIAL" / iana-token classvalue = "PUBLIC" / "PRIVATE" / "CONFIDENTIAL" / iana-token
/ x-name / x-name
;Default is PUBLIC ;Default is PUBLIC
Example: The following is an example of this property: Example: The following is an example of this property:
CLASS:PUBLIC CLASS:PUBLIC
3.8.1.4. Comment 3.8.1.4. Comment
Property Name: COMMENT Property Name: COMMENT
Purpose: This property specifies non-processing information intended Purpose: This property specifies non-processing information intended
to provide a comment to the calendar user. to provide a comment to the calendar user.
Value Type: TEXT Value Type: TEXT
Property Parameters: IANA, non-standard, alternate text Property Parameters: IANA, non-standard, alternate text
representation and language property parameters can be specified representation, and language property parameters can be specified
on this property. on this property.
RFC 5545 iCalendar September 2009
Conformance: This property can be specified multiple times in Conformance: This property can be specified multiple times in
"VEVENT", "VTODO", "VJOURNAL", and "VFREEBUSY" calendar components "VEVENT", "VTODO", "VJOURNAL", and "VFREEBUSY" calendar components
as well as in the "STANDARD" and "DAYLIGHT" sub-components. as well as in the "STANDARD" and "DAYLIGHT" sub-components.
Description: This property is used to specify a comment to the Description: This property is used to specify a comment to the
calendar user. calendar user.
Format Definition: This property is defined by the following Format Definition: This property is defined by the following
notation: notation:
comment = "COMMENT" commparam ":" text CRLF comment = "COMMENT" commparam ":" text CRLF
commparam = *( commparam = *(
; ;
; the following are OPTIONAL, ; The following are OPTIONAL,
; but MUST NOT occur more than once ; but MUST NOT occur more than once.
; ;
(";" altrepparam) / (";" languageparam) / (";" altrepparam) / (";" languageparam) /
; ;
; the following is OPTIONAL, ; The following is OPTIONAL,
; and MAY occur more than once ; and MAY occur more than once.
; ;
(";" other-param) (";" other-param)
; ;
) )
Example: The following is an example of this property: Example: The following is an example of this property:
COMMENT:The meeting really needs to include both ourselves COMMENT:The meeting really needs to include both ourselves
and the customer. We can't hold this meeting without them. and the customer. We can't hold this meeting without them.
As a matter of fact\, the venue for the meeting ought to be at As a matter of fact\, the venue for the meeting ought to be at
their site. - - John their site. - - John
3.8.1.5. Description 3.8.1.5. Description
Property Name: DESCRIPTION Property Name: DESCRIPTION
Purpose: This property provides a more complete description of the Purpose: This property provides a more complete description of the
calendar component, than that provided by the "SUMMARY" property. calendar component than that provided by the "SUMMARY" property.
Value Type: TEXT Value Type: TEXT
Property Parameters: IANA, non-standard, alternate text Property Parameters: IANA, non-standard, alternate text
representation and language property parameters can be specified representation, and language property parameters can be specified
on this property. on this property.
RFC 5545 iCalendar September 2009
Conformance: The property can be specified in the "VEVENT", "VTODO", Conformance: The property can be specified in the "VEVENT", "VTODO",
"VJOURNAL" or "VALARM" calendar components. The property can be "VJOURNAL", or "VALARM" calendar components. The property can be
specified multiple times only within a "VJOURNAL" calendar specified multiple times only within a "VJOURNAL" calendar
component. component.
Description: This property is used in the "VEVENT" and "VTODO" to Description: This property is used in the "VEVENT" and "VTODO" to
capture lengthy textual decriptions associated with the activity. capture lengthy textual descriptions associated with the activity.
This property is used in the "VJOURNAL" calendar component to This property is used in the "VJOURNAL" calendar component to
capture one or more textual journal entries. capture one or more textual journal entries.
This property is used in the "VALARM" calendar component to This property is used in the "VALARM" calendar component to
capture the display text for a DISPLAY category of alarm, and to capture the display text for a DISPLAY category of alarm, and to
capture the body text for an EMAIL category of alarm. capture the body text for an EMAIL category of alarm.
Format Definition: This property is defined by the following Format Definition: This property is defined by the following
notation: notation:
description = "DESCRIPTION" descparam ":" text CRLF description = "DESCRIPTION" descparam ":" text CRLF
descparam = *( descparam = *(
; ;
; the following are OPTIONAL, ; The following are OPTIONAL,
; but MUST NOT occur more than once ; but MUST NOT occur more than once.
; ;
(";" altrepparam) / (";" languageparam) / (";" altrepparam) / (";" languageparam) /
; ;
; the following is OPTIONAL, ; The following is OPTIONAL,
; and MAY occur more than once ; and MAY occur more than once.
; ;
(";" other-param) (";" other-param)
; ;
) )
Example: The following is an example of this property with formatted Example: The following is an example of this property with formatted
line breaks in the property value: line breaks in the property value:
DESCRIPTION:Meeting to provide technical review for "Phoenix" DESCRIPTION:Meeting to provide technical review for "Phoenix"
design.\nHappy Face Conference Room. Phoenix design team design.\nHappy Face Conference Room. Phoenix design team
MUST attend this meeting.\nRSVP to team leader. MUST attend this meeting.\nRSVP to team leader.
3.8.1.6. Geographic Position 3.8.1.6. Geographic Position
Property Name: GEO Property Name: GEO
Purpose: This property specifies information related to the global Purpose: This property specifies information related to the global
position for the activity specified by a calendar component. position for the activity specified by a calendar component.
Value Type: FLOAT. The value MUST be two SEMICOLON separated FLOAT RFC 5545 iCalendar September 2009