draft-ietf-calsify-rfc2445bis-00.txt   draft-ietf-calsify-rfc2445bis-01.txt 
Network Working Group B. Desruisseaux, Ed. Network Working Group B. Desruisseaux, Ed.
Internet-Draft Oracle Internet-Draft Oracle
Expires: April 14, 2006 C. Stoner, Ed. Obsoletes: 2445 (if approved) June 22, 2006
IBM Expires: December 24, 2006
October 11, 2005
Internet Calendaring and Scheduling Core Object Specification Internet Calendaring and Scheduling Core Object Specification
(iCalendar) (iCalendar)
draft-ietf-calsify-rfc2445bis-00 draft-ietf-calsify-rfc2445bis-01
Status of this Memo Status of this Memo
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applicable patent or other IPR claims of which he or she is aware applicable patent or other IPR claims of which he or she is aware
have been or will be disclosed, and any of which he or she becomes have been or will be disclosed, and any of which he or she becomes
aware will be disclosed, in accordance with Section 6 of BCP 79. aware will be disclosed, in accordance with Section 6 of BCP 79.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that Task Force (IETF), its areas, and its working groups. Note that
skipping to change at page 1, line 36 skipping to change at page 1, line 35
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This Internet-Draft will expire on April 14, 2006. This Internet-Draft will expire on December 24, 2006.
Copyright Notice Copyright Notice
Copyright (C) The Internet Society (2005). Copyright (C) The Internet Society (2006).
Abstract Abstract
Calendar systems export, transport and sometimes even store calendar There is a clear need to provide and deploy interoperable calendaring
information in a standard, interoperable format. This memo defines and scheduling services for the Internet. Current group scheduling
the common format for openly exchanging calendaring and scheduling and Personal Information Management (PIM) products are being extended
information across the Internet, known as the iCalendar object for use across the Internet, today, in proprietary ways. This memo
format. An iCalendar object may represent an event, to-do or task, has been defined to provide the definition of a common format for
or journal entry (note). openly exchanging calendaring and scheduling information across the
Internet.
Comments are solicited and should be addressed to the working group's This memo is formatted as a registration for a MIME media type .
mailing list at ietf-calsify@osafoundation.org and/or the editor. However, the format in this memo is equally applicable for use
outside of a MIME message content type.
The proposed media type value is 'text/calendar'. This string would
label a media type containing calendaring and scheduling information
encoded as text characters formatted in a manner outlined below.
This MIME media type provides a standard content type for capturing
calendar event, to-do and journal entry information. It also can be
used to convey free/busy time information. The content type is
suitable as a MIME message entity that can be transferred over MIME
based email systems, using HTTP or some other Internet transport. In
addition, the content type is useful as an object for interactions
between desktop applications using the operating system clipboard,
drag/drop or file systems capabilities.
This memo is based on the earlier work of the vCalendar specification
for the exchange of personal calendaring and scheduling information.
In order to avoid confusion with this referenced work, this memo is
to be known as the iCalendar specification.
This memo defines the format for specifying iCalendar object methods.
An iCalendar object method is a set of usage constraints for the
iCalendar object. For example, these methods might define scheduling
messages that request an event be scheduled, reply to an event
request, send a cancellation notice for an event, modify or replace
the definition of an event, provide a counter proposal for an
original event request, delegate an event request to another
individual, request free or busy time, reply to a free or busy time
request, or provide similar scheduling messages for a to-do or
journal entry calendar component. The iCalendar Transport-indendent
Interoperability Protocol (iTIP) is one such scheduling protocol.
Editorial Note
This document is a product of the Calendaring and Scheduling
Standards Simplification (Calsify) working group of the Internet
Engineering Task Force. Comments on this draft are welcomed, and
should be addressed to the ietf-calsify@osafoundation.org [1] mailing
list.
A detailed list of changes is available at the following page:
http://www.geocities.com/bdesruisseaux/calsify/
draft-ietf-calsify-rfc2445bis-01.html.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 6
1.1. Related Memos . . . . . . . . . . . . . . . . . . . . . 5 2. Basic Grammar and Conventions . . . . . . . . . . . . . . . . 6
2. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.1. Formatting Conventions . . . . . . . . . . . . . . . . . 7
3. Document Conventions . . . . . . . . . . . . . . . . . . . . 8 2.2. Related Memos . . . . . . . . . . . . . . . . . . . . . . 8
3.1. Formatting Conventions . . . . . . . . . . . . . . . . . 8 2.3. International Considerations . . . . . . . . . . . . . . 8
4. International Considerations . . . . . . . . . . . . . . . . 10 3. iCalendar Object Specification . . . . . . . . . . . . . . . 9
5. General Syntax . . . . . . . . . . . . . . . . . . . . . . . 11 3.1. Content Lines . . . . . . . . . . . . . . . . . . . . . . 9
5.1. Character Set . . . . . . . . . . . . . . . . . . . . . 11 3.1.1. List and Field Separators . . . . . . . . . . . . . . 11
5.2. Case Sensitivity . . . . . . . . . . . . . . . . . . . . 11 3.1.2. Multiple Values . . . . . . . . . . . . . . . . . . . 12
5.3. Content Lines . . . . . . . . . . . . . . . . . . . . . 11 3.1.3. Binary Content . . . . . . . . . . . . . . . . . . . 12
5.4. List and Field Separators . . . . . . . . . . . . . . . 14 3.1.4. Character Set . . . . . . . . . . . . . . . . . . . . 13
5.5. Multiple Property Values . . . . . . . . . . . . . . . . 14 3.2. Property Parameters . . . . . . . . . . . . . . . . . . . 13
5.6. Binary Content . . . . . . . . . . . . . . . . . . . . . 15 3.2.1. Alternate Text Representation . . . . . . . . . . . . 14
5.7. Property Parameter Syntax . . . . . . . . . . . . . . . 15 3.2.2. Common Name . . . . . . . . . . . . . . . . . . . . . 15
6. iCalendar Objects . . . . . . . . . . . . . . . . . . . . . . 17 3.2.3. Calendar User Type . . . . . . . . . . . . . . . . . 16
7. Calendar Components . . . . . . . . . . . . . . . . . . . . . 18 3.2.4. Delegators . . . . . . . . . . . . . . . . . . . . . 16
7.1. Event Component . . . . . . . . . . . . . . . . . . . . 19 3.2.5. Delegatees . . . . . . . . . . . . . . . . . . . . . 17
7.2. To-do Component . . . . . . . . . . . . . . . . . . . . 22 3.2.6. Directory Entry Reference . . . . . . . . . . . . . . 17
7.3. Journal Component . . . . . . . . . . . . . . . . . . . 24 3.2.7. Inline Encoding . . . . . . . . . . . . . . . . . . . 18
7.4. Free/Busy Component . . . . . . . . . . . . . . . . . . 26 3.2.8. Format Type . . . . . . . . . . . . . . . . . . . . . 19
7.5. Time Zone Component . . . . . . . . . . . . . . . . . . 29 3.2.9. Free/Busy Time Type . . . . . . . . . . . . . . . . . 19
7.6. Alarm Component . . . . . . . . . . . . . . . . . . . . 38 3.2.10. Language . . . . . . . . . . . . . . . . . . . . . . 20
8. Properties . . . . . . . . . . . . . . . . . . . . . . . . . 45 3.2.11. Group or List Membership . . . . . . . . . . . . . . 21
8.1. Calendar Properties . . . . . . . . . . . . . . . . . . 45 3.2.12. Participation Status . . . . . . . . . . . . . . . . 21
8.1.1. Calendar Scale . . . . . . . . . . . . . . . . . . . 45 3.2.13. Recurrence Identifier Range . . . . . . . . . . . . . 23
8.1.2. Method . . . . . . . . . . . . . . . . . . . . . . . 46 3.2.14. Alarm Trigger Relationship . . . . . . . . . . . . . 23
8.1.3. Product Identifier . . . . . . . . . . . . . . . . . 47 3.2.15. Relationship Type . . . . . . . . . . . . . . . . . . 24
8.1.4. Version . . . . . . . . . . . . . . . . . . . . . . . 48 3.2.16. Participation Role . . . . . . . . . . . . . . . . . 25
8.2. Descriptive Component Properties . . . . . . . . . . . . 49 3.2.17. RSVP Expectation . . . . . . . . . . . . . . . . . . 25
8.2.1. Attachment . . . . . . . . . . . . . . . . . . . . . 49 3.2.18. Sent By . . . . . . . . . . . . . . . . . . . . . . . 26
8.2.2. Categories . . . . . . . . . . . . . . . . . . . . . 50 3.2.19. Time Zone Identifier . . . . . . . . . . . . . . . . 26
8.2.3. Classification . . . . . . . . . . . . . . . . . . . 51 3.2.20. Value Data Types . . . . . . . . . . . . . . . . . . 28
8.2.4. Comment . . . . . . . . . . . . . . . . . . . . . . . 52 3.3. Property Value Data Types . . . . . . . . . . . . . . . . 29
8.2.5. Description . . . . . . . . . . . . . . . . . . . . . 53 3.3.1. Binary . . . . . . . . . . . . . . . . . . . . . . . 29
8.2.6. Geographic Position . . . . . . . . . . . . . . . . . 54 3.3.2. Boolean . . . . . . . . . . . . . . . . . . . . . . . 30
8.2.7. Location . . . . . . . . . . . . . . . . . . . . . . 56 3.3.3. Calendar User Address . . . . . . . . . . . . . . . . 30
8.2.8. Percent Complete . . . . . . . . . . . . . . . . . . 57 3.3.4. Date . . . . . . . . . . . . . . . . . . . . . . . . 31
8.2.9. Priority . . . . . . . . . . . . . . . . . . . . . . 58 3.3.5. Date-Time . . . . . . . . . . . . . . . . . . . . . . 31
8.2.10. Resources . . . . . . . . . . . . . . . . . . . . . . 59 3.3.6. Duration . . . . . . . . . . . . . . . . . . . . . . 34
8.2.11. Free/Busy Time Type . . . . . . . . . . . . . . . . . 60 3.3.7. Float . . . . . . . . . . . . . . . . . . . . . . . . 34
8.2.12. Participation Status . . . . . . . . . . . . . . . . 61 3.3.8. Integer . . . . . . . . . . . . . . . . . . . . . . . 35
8.2.13. Status . . . . . . . . . . . . . . . . . . . . . . . 63 3.3.9. Period of Time . . . . . . . . . . . . . . . . . . . 35
8.2.14. Summary . . . . . . . . . . . . . . . . . . . . . . . 64 3.3.10. Recurrence Rule . . . . . . . . . . . . . . . . . . . 37
8.2.15. Date and Time Component Properties . . . . . . . . . 65 3.3.11. Text . . . . . . . . . . . . . . . . . . . . . . . . 42
8.2.16. Time Zone Component Properties . . . . . . . . . . . 73 3.3.12. Time . . . . . . . . . . . . . . . . . . . . . . . . 43
8.2.17. Relationship Component Properties . . . . . . . . . . 77 3.3.13. URI . . . . . . . . . . . . . . . . . . . . . . . . . 46
8.2.18. Calendar User Type . . . . . . . . . . . . . . . . . 86 3.3.14. UTC Offset . . . . . . . . . . . . . . . . . . . . . 46
8.2.19. Directory Entry Reference . . . . . . . . . . . . . . 87 3.4. iCalendar Object . . . . . . . . . . . . . . . . . . . . 47
8.2.20. Recurrence ID . . . . . . . . . . . . . . . . . . . . 87 3.5. Property . . . . . . . . . . . . . . . . . . . . . . . . 48
8.2.21. Related To . . . . . . . . . . . . . . . . . . . . . 89 3.6. Calendar Components . . . . . . . . . . . . . . . . . . . 48
8.2.22. Uniform Resource Locator . . . . . . . . . . . . . . 91 3.6.1. Event Component . . . . . . . . . . . . . . . . . . . 49
8.2.23. Unique Identifier . . . . . . . . . . . . . . . . . . 91 3.6.2. To-do Component . . . . . . . . . . . . . . . . . . . 52
8.2.24. Relationship Type . . . . . . . . . . . . . . . . . . 93 3.6.3. Journal Component . . . . . . . . . . . . . . . . . . 54
8.3. Recurrence Component Properties . . . . . . . . . . . . 94 3.6.4. Free/Busy Component . . . . . . . . . . . . . . . . . 55
8.3.1. Exception Date/Times . . . . . . . . . . . . . . . . 94 3.6.5. Time Zone Component . . . . . . . . . . . . . . . . . 58
8.3.2. Exception Rule . . . . . . . . . . . . . . . . . . . 95 3.6.6. Alarm Component . . . . . . . . . . . . . . . . . . . 66
8.3.3. Recurrence Date/Times . . . . . . . . . . . . . . . . 97 3.7. Calendar Properties . . . . . . . . . . . . . . . . . . . 72
8.3.4. Recurrence Identifier Range . . . . . . . . . . . . . 98 3.7.1. Calendar Scale . . . . . . . . . . . . . . . . . . . 72
8.3.5. Recurrence Rule . . . . . . . . . . . . . . . . . . . 99 3.7.2. Method . . . . . . . . . . . . . . . . . . . . . . . 73
8.4. Alarm Component Properties . . . . . . . . . . . . . . . 110 3.7.3. Product Identifier . . . . . . . . . . . . . . . . . 74
8.4.1. Action . . . . . . . . . . . . . . . . . . . . . . . 110 3.7.4. Version . . . . . . . . . . . . . . . . . . . . . . . 75
8.4.2. Alarm Repeat Count . . . . . . . . . . . . . . . . . 111 3.8. Component Properties . . . . . . . . . . . . . . . . . . 76
8.4.3. Alarm Trigger . . . . . . . . . . . . . . . . . . . . 111 3.8.1. Descriptive Component Properties . . . . . . . . . . 76
8.5. Alarm Trigger Relationship . . . . . . . . . . . . . . . 114 3.8.1.1. Attachment . . . . . . . . . . . . . . . . . . . 76
8.6. Change Management Component Properties . . . . . . . . . 114 3.8.1.2. Categories . . . . . . . . . . . . . . . . . . . 77
8.6.1. Date/Time Created . . . . . . . . . . . . . . . . . . 114 3.8.1.3. Classification . . . . . . . . . . . . . . . . . 78
8.6.2. Date/Time Stamp . . . . . . . . . . . . . . . . . . . 115 3.8.1.4. Comment . . . . . . . . . . . . . . . . . . . . . 79
8.6.3. Last Modified . . . . . . . . . . . . . . . . . . . . 116 3.8.1.5. Description . . . . . . . . . . . . . . . . . . . 80
8.6.4. Sequence Number . . . . . . . . . . . . . . . . . . . 117 3.8.1.6. Geographic Position . . . . . . . . . . . . . . . 81
8.7. Miscellaneous Component Properties . . . . . . . . . . . 118 3.8.1.7. Location . . . . . . . . . . . . . . . . . . . . 83
8.7.1. RSVP Expectation . . . . . . . . . . . . . . . . . . 118 3.8.1.8. Percent Complete . . . . . . . . . . . . . . . . 84
8.7.2. Language . . . . . . . . . . . . . . . . . . . . . . 119 3.8.1.9. Priority . . . . . . . . . . . . . . . . . . . . 85
8.7.3. Group or List Membership . . . . . . . . . . . . . . 120 3.8.1.10. Resources . . . . . . . . . . . . . . . . . . . . 87
8.7.4. Alternate Text Representation . . . . . . . . . . . . 121 3.8.1.11. Status . . . . . . . . . . . . . . . . . . . . . 87
8.7.5. Inline Encoding . . . . . . . . . . . . . . . . . . . 121 3.8.1.12. Summary . . . . . . . . . . . . . . . . . . . . . 89
8.7.6. Format Type . . . . . . . . . . . . . . . . . . . . . 122 3.8.2. Date and Time Component Properties . . . . . . . . . 90
8.7.7. Non-standard Properties . . . . . . . . . . . . . . . 123 3.8.2.1. Date/Time Completed . . . . . . . . . . . . . . . 90
8.7.8. Request Status . . . . . . . . . . . . . . . . . . . 124 3.8.2.2. Date/Time End . . . . . . . . . . . . . . . . . . 91
9. iCalendar Object Examples . . . . . . . . . . . . . . . . . . 127 3.8.2.3. Date/Time Due . . . . . . . . . . . . . . . . . . 92
10. Recommended Practices . . . . . . . . . . . . . . . . . . . . 132 3.8.2.4. Date/Time Start . . . . . . . . . . . . . . . . . 93
11. Registration of Content Type Elements . . . . . . . . . . . . 134 3.8.2.5. Duration . . . . . . . . . . . . . . . . . . . . 94
11.1. Registration of New and Modified iCalendar Object 3.8.2.6. Free/Busy Time . . . . . . . . . . . . . . . . . 95
Methods . . . . . . . . . . . . . . . . . . . . . . . . 134 3.8.2.7. Time Transparency . . . . . . . . . . . . . . . . 96
11.2. Registration of New Properties . . . . . . . . . . . . . 134 3.8.3. Time Zone Component Properties . . . . . . . . . . . 97
11.3. Define the property . . . . . . . . . . . . . . . . . . 134 3.8.3.1. Time Zone Identifier . . . . . . . . . . . . . . 98
11.4. Post the Property definition . . . . . . . . . . . . . . 136 3.8.3.2. Time Zone Name . . . . . . . . . . . . . . . . . 99
11.5. Allow a comment period . . . . . . . . . . . . . . . . . 136 3.8.3.3. Time Zone Offset From . . . . . . . . . . . . . . 100
11.6. Submit the property for approval . . . . . . . . . . . . 136 3.8.3.4. Time Zone Offset To . . . . . . . . . . . . . . . 101
11.7. Property Change Control . . . . . . . . . . . . . . . . 136 3.8.3.5. Time Zone URL . . . . . . . . . . . . . . . . . . 101
12. Property Parameters . . . . . . . . . . . . . . . . . . . . . 138 3.8.4. Relationship Component Properties . . . . . . . . . . 102
13. Value Data Types . . . . . . . . . . . . . . . . . . . . . . 139 3.8.4.1. Attendee . . . . . . . . . . . . . . . . . . . . 102
13.1. Binary . . . . . . . . . . . . . . . . . . . . . . . . . 139 3.8.4.2. Contact . . . . . . . . . . . . . . . . . . . . . 105
13.2. Boolean . . . . . . . . . . . . . . . . . . . . . . . . 140 3.8.4.3. Organizer . . . . . . . . . . . . . . . . . . . . 106
13.3. Calendar User Address . . . . . . . . . . . . . . . . . 140 3.8.4.4. Recurrence ID . . . . . . . . . . . . . . . . . . 108
13.4. Date . . . . . . . . . . . . . . . . . . . . . . . . . . 141 3.8.4.5. Related To . . . . . . . . . . . . . . . . . . . 110
13.5. Date-Time . . . . . . . . . . . . . . . . . . . . . . . 141 3.8.4.6. Uniform Resource Locator . . . . . . . . . . . . 112
13.6. Duration . . . . . . . . . . . . . . . . . . . . . . . . 143 3.8.4.7. Unique Identifier . . . . . . . . . . . . . . . . 112
13.7. Period of Time . . . . . . . . . . . . . . . . . . . . . 144 3.8.5. Recurrence Component Properties . . . . . . . . . . . 114
13.8. Time Zone Identifier . . . . . . . . . . . . . . . . . . 145 3.8.5.1. Exception Date/Times . . . . . . . . . . . . . . 114
13.9. Recurrence Rule . . . . . . . . . . . . . . . . . . . . 146 3.8.5.2. Exception Rule . . . . . . . . . . . . . . . . . 115
13.10. Float . . . . . . . . . . . . . . . . . . . . . . . . . 152 3.8.5.3. Recurrence Date/Times . . . . . . . . . . . . . . 117
13.11. Integer . . . . . . . . . . . . . . . . . . . . . . . . 152 3.8.5.4. Recurrence Rule . . . . . . . . . . . . . . . . . 118
13.12. Text . . . . . . . . . . . . . . . . . . . . . . . . . . 153 3.8.6. Alarm Component Properties . . . . . . . . . . . . . 127
13.13. Time . . . . . . . . . . . . . . . . . . . . . . . . . . 154 3.8.6.1. Action . . . . . . . . . . . . . . . . . . . . . 128
13.14. URI . . . . . . . . . . . . . . . . . . . . . . . . . . 156 3.8.6.2. Repeat Count . . . . . . . . . . . . . . . . . . 128
13.15. UTC Offset . . . . . . . . . . . . . . . . . . . . . . . 157 3.8.6.3. Trigger . . . . . . . . . . . . . . . . . . . . . 129
14. Security Considerations . . . . . . . . . . . . . . . . . . . 159 3.8.7. Change Management Component Properties . . . . . . . 131
15. IANA MIME Media Type Registration . . . . . . . . . . . . . . 160 3.8.7.1. Date/Time Created . . . . . . . . . . . . . . . . 132
16. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 163 3.8.7.2. Date/Time Stamp . . . . . . . . . . . . . . . . . 132
17. Normative References . . . . . . . . . . . . . . . . . . . . 163 3.8.7.3. Last Modified . . . . . . . . . . . . . . . . . . 133
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 165 3.8.7.4. Sequence Number . . . . . . . . . . . . . . . . . 134
Intellectual Property and Copyright Statements . . . . . . . . . 166 3.8.8. Miscellaneous Component Properties . . . . . . . . . 136
3.8.8.1. Non-standard Properties . . . . . . . . . . . . . 136
3.8.8.2. Request Status . . . . . . . . . . . . . . . . . 137
4. iCalendar Object Examples . . . . . . . . . . . . . . . . . . 140
5. Recommended Practices . . . . . . . . . . . . . . . . . . . . 144
6. Registration of Content Type Elements . . . . . . . . . . . . 145
6.1. Registration of New and Modified iCalendar Object
Methods . . . . . . . . . . . . . . . . . . . . . . . . . 145
6.2. Registration of New Properties . . . . . . . . . . . . . 145
6.2.1. Define the property . . . . . . . . . . . . . . . . . 146
6.2.2. Post the Property definition . . . . . . . . . . . . 147
6.2.3. Allow a comment period . . . . . . . . . . . . . . . 147
6.2.4. Submit the property for approval . . . . . . . . . . 147
6.3. Property Change Control . . . . . . . . . . . . . . . . . 148
7. Internationalization Considerations . . . . . . . . . . . . . 148
8. Security Considerations . . . . . . . . . . . . . . . . . . . 148
9. IANA Consideration . . . . . . . . . . . . . . . . . . . . . 149
9.1. Media Type Registration Information . . . . . . . . . . . 149
10. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 152
11. References . . . . . . . . . . . . . . . . . . . . . . . . . 152
11.1. Normative References . . . . . . . . . . . . . . . . . . 152
11.2. Informative References . . . . . . . . . . . . . . . . . 153
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 155
Intellectual Property and Copyright Statements . . . . . . . . . 156
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. However, the longer term growth of information technology. However, the longer term growth of
calendaring and scheduling, is currently limited by the lack of calendaring and scheduling, is currently limited by the lack of
Internet standards for the message content types that are central to Internet standards for the message content types that are central to
these knowledgeware applications. This memo is intended to progress these knowledgeware applications. This memo is intended to progress
the level of interoperability possible between dissimilar calendaring the level of interoperability possible between dissimilar calendaring
and scheduling applications. This memo defines a MIME [5] content and scheduling applications. This memo defines a MIME content type
type for exchanging electronic calendaring and scheduling for exchanging electronic calendaring and scheduling information.
information. The Internet Calendaring and Scheduling Core Object The Internet Calendaring and Scheduling Core Object Specification, or
Specification, or iCalendar, allows for the capture and exchange of iCalendar, allows for the capture and exchange of information
information normally stored within a calendaring and scheduling normally stored within a calendaring and scheduling application; such
application; such as a Personal Information Manager or a Group as a Personal Information Manager (PIM) or a Group Scheduling
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 might also be used.
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 a requesting for and
replying with free/busy time data. [[Comment.1: Removed forward replying with free/busy time data. Such a scheduling protocol is
reference to ITIP (unnecessary) --Lisa D]] defined in the iCalendar Transport-independent Interoperability
Protocol (iTIP) defined in [I-D.ietf-calsify-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 RFC 2234 [8]. This ABNF is required for the Internet ABNF defined in [RFC2234]. 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. descriptive prose definition of the memo.
1.1. Related Memos 2. Basic Grammar and Conventions
Implementers will need to be familiar with several other memos that,
along with this memo, form a framework for Internet calendaring and
scheduling standards. This memo, [ICAL], specifies a core
specification of objects, data types, properties and property
parameters.
[ITIP] - specifies an interoperability protocol for scheduling
between different implementations;
[IMIP] specifies an Internet email binding for [ITIP].
This memo does not attempt to repeat the specification of concepts or
definitions from these other memos. Where possible, references are
made to the memo that provides for the specification of these
concepts or definitions. [[Comment.2: If we keep this section on
related memos, we have to think about whether ITIP and IMIP are
progressing to Draft at the same time, whether to update those
references and whether to add CalDAV or other references. --Lisa D]]
2. Overview
This draft section provides a high-level overview of the concepts of
iCalendar and the organization of this document.
An iCalendar object contains a set of calendar properties and a set
of components. Components consist of a set of component properties.
Properties consist of a property name, a set of parameters, and a
property value.
The preliminary material of this document includes the introduction,
this overview, some document conventions and the considerations for
internationalization.
Section 5 provides the general syntax rules used by all of iCalendar,
such as character set, line length and line break rules, and which
characters are separators.
Section 6 defines the iCalendar object itself, and Section 7 covers
the components that appear in iCalendar objects.
3. Document 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", "NOT RECOMMENDED", "MAY" and "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY" and
"OPTIONAL" in this document are to be interoperated as described in "OPTIONAL" in this document are to be interoperated as described in
RFC 2119 [7]. [RFC2119].
This memo makes use of both a descriptive prose and a more formal This memo makes use of both a descriptive prose and a more formal
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 RFC 2234 [8]. The notation used in this memo is the ABNF notation of [RFC2234].
Readers intending on implementing this format defined in this memo Readers intending on implementing this 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.
Note: All indented editorial notes, such as this one, are intended to All numeric values used in this memo are given in decimal notation.
provide the reader with additional information. The information is
not essential to the building of an implementation conformant with
this memo. The information is provided to highlight a particular
feature or characteristic of the memo. [[Comment.3: This section can
be deleted because it provides practically no information and is not
a normative reference: The format for the iCalendar object is based
on the syntax of the RFC 2425 content type. While the iCalendar
object is not a profile of the RFC 2425 content type, it does reuse a
number of the elements from the RFC 2425 specification. --Lisa D]]
3.1. Formatting Conventions All names of properties, property parameters, enumerated property
values and property parameter values are case-insensitive. However,
all other property values are case-sensitive, unless otherwise
stated.
Note: All indented editorial notes, such as this one, are intended
to provide the reader with additional information. The
information is not essential to the building of an implementation
conformant with this memo. The information is provided to
highlight a particular feature or characteristic of the memo.
The format for the iCalendar object is based on the syntax of the
[RFC2425] content type. While the iCalendar object is not a profile
of the [RFC2425] content type, it does reuse a number of the elements
from the [RFC2425] specification.
2.1. Formatting Conventions
The mechanisms defined in this memo are defined in prose. Many of The mechanisms defined in this memo are defined in prose. Many of
the terms used to describe these have common usage that is different the terms used to describe these have common usage that is different
than the standards usage of this memo. In order to reference within than the standards usage of this memo. In order to reference within
this memo elements of the calendaring and scheduling model, core this memo elements of the calendaring and scheduling model, core
object (this memo) or interoperability protocol [ITIP] some object (this memo) or interoperability protocol [I-D.ietf-calsify-
formatting conventions have been used. Calendaring and scheduling 2446bis] some formatting conventions have been used. Calendaring and
roles are referred to in quoted-strings of text with the first scheduling roles are referred to in quoted-strings of text with the
character of each word in upper case. For example, "Organizer" first character of each word in upper case. For example, "Organizer"
refers to a role of a "Calendar User" within the scheduling protocol refers to a role of a "Calendar User" within the scheduling protocol
defined by [ITIP]. Calendar components defined by this memo are defined by [I-D.ietf-calsify-2446bis]. Calendar components defined
referred to with capitalized, quoted-strings of text. All calendar by this memo are referred to with capitalized, quoted-strings of
components start with the letter "V". For example, "VEVENT" refers text. All calendar components start with the letter "V". For
to the event calendar component, "VTODO" refers to the to-do calendar example, "VEVENT" refers to the event calendar component, "VTODO"
component and "VJOURNAL" refers to the daily journal calendar refers to the to-do calendar component and "VJOURNAL" refers to the
component. Scheduling methods defined by [ITIP] are referred to with daily journal calendar component. Scheduling methods defined by iTIP
capitalized, quoted-strings of text. For example, "REQUEST" refers [I-D.ietf-calsify-2446bis] are referred to with capitalized, quoted-
to the method for requesting a scheduling calendar component be strings of text. For example, "REQUEST" refers to the method for
created or modified, "REPLY" refers to the method a recipient of a requesting a scheduling calendar component be created or modified,
request uses to update their status with the "Organizer" of the "REPLY" refers to the method a recipient of a request uses to update
calendar component. 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 data type for a property value. Enumerated values the default data 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" data type value can be used with the "FREQ" component of the "RECUR" data 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.
4. International Considerations 2.2. Related Memos
Implementers will need to be familiar with several other memos that,
along with this memo, form a framework for Internet calendaring and
scheduling standards. This memo specifies a core specification of
objects, data types, properties and property parameters.
o iTIP [I-D.ietf-calsify-2446bis] specifies an interoperability
protocol for scheduling between different implementations;
o iMIP [I-D.ietf-calsify-rfc2447bis] specifies an Internet email
binding for [I-D.ietf-calsify-2446bis].
This memo does not attempt to repeat the specification of concepts or
definitions from these other memos. Where possible, references are
made to the memo that provides for the specification of these
concepts or definitions.
2.3. International Considerations
In the rest of this document, descriptions of characters are of the In the rest of this document, descriptions of characters are of the
form "character name (codepoint)", where "codepoint" is from the US- form "character name (codepoint)", where "codepoint" is from the US-
ASCII character set. The "character name" is the authoritative ASCII character set. The "character name" is the authoritative
description; (codepoint) is a reference to that character in US-ASCII description; (codepoint) is a reference to that character in US-ASCII
or US-ASCII compatible sets (for example the ISO-8859-x family, UTF- or US-ASCII compatible sets (for example the ISO-8859-x family, UTF-
8, ISO-2022-xx, KOI8-R). If a non-US-ASCII compatible character set 8, ISO-2022-xx, KOI8-R). If a non-US-ASCII compatible character set
is used, appropriate code-point from that character set MUST be is used, appropriate code-point from that character set MUST be
chosen instead. Use of non-US-ASCII-compatible character sets is NOT chosen instead. Use of non-US-ASCII-compatible character sets is NOT
recommended. recommended.
5. General Syntax 3. iCalendar Object Specification
5.1. Character Set
The default character set for an iCalendar object is UTF-8 as defined
in RFC 2279 [9]. The "charset" Content-Type parameter can be used in
MIME transports to specify any other IANA registered character set.
[[Comment.4: I think we need to say something about interoperability
problems which result from using any other charset. --Lisa D]]
5.2. Case Sensitivity
All names of properties, property parameters, enumerated property The following sections define the details of a Calendaring and
values and property parameter values are case-insensitive. However, Scheduling Core Object Specification. This information is intended
all other property values are case-sensitive, unless otherwise to be an integral part of the MIME content type registration. In
stated. addition, this information can be used independent of such content
registration. In particular, this memo has direct applicability for
use as a calendaring and scheduling exchange format in file-, memory-
or network-based transport mechanisms.
5.3. 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 (US-ASCII decimal 13, followed by US-ASCII
decimal 10). 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 the 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, US-ASCII decimal 32 or HTAB, US-ASCII decimal 9). Any
sequence of CRLF followed immediately by a single linear white space sequence of CRLF followed immediately by a single linear white space
character is ignored (i.e., removed) when processing the content character is ignored (i.e., removed) when 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.
Figure 1
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.
Figure 2
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 character and the linear white
space character that immediately follows. space character that immediately follows.
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. When according to the unfolding procedure described above. When
generating a content line, lines longer than 75 octets SHOULD be generating a content line, lines longer than 75 octets SHOULD be
folded according to the folding procedure described above. Content folded according to the folding procedure described above.
lines are CRLF-separated. [[Comment.5: Removed reference to 2425
again and simply stated that lines are CRLF-separated --Lisa]]
The following ABNF defines the lines of content in an iCalendar The content information associated with an iCalendar object is
formatted using a syntax similar to that defined by [RFC2425]. That
is, the content information consists of CRLF-separated content lines.
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 = x-name / iana-token name = x-name / iana-token
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 / "-")
; Reservered for experimental use. Not intended for use in ; Reserved for experimental use.
; released products.
vendorid = 3*(ALPHA / DIGIT) ;Vendor identification vendorid = 3*(ALPHA / DIGIT) ;Vendor identification
param = param-name "=" param-value param = param-name "=" param-value
*("," 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-token param-name = iana-token / x-token
skipping to change at page 13, line 48 skipping to change at page 11, line 39
DQUOTE = %x22 DQUOTE = %x22
; Quotation Mark ; Quotation Mark
WSP = SPACE / HTAB WSP = SPACE / HTAB
SPACE = %x20 SPACE = %x20
HTAB = %x09 HTAB = %x09
Figure 3
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.
5.4. 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 (US-ASCII
decimal 44). There is no significance to the order of values in a decimal 44). There is no significance to the order of values in a
list. For those parameter values (such as those that specify URI list. For those parameter values (such as those that specify URI
values) that are specified in quoted-strings, the individual quoted- values) that are specified in quoted-strings, the individual quoted-
strings are separated by a COMMA character (US-ASCII decimal 44). strings are separated by a COMMA character (US-ASCII decimal 44).
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
skipping to change at page 14, line 40 skipping to change at page 12, line 29
For example, in the following properties a SEMICOLON is used to For example, in the following properties a SEMICOLON is used to
separate property parameters from each other, and a COMMA is used to separate property parameters from each other, and a COMMA is used to
separate property values in a value list. separate property values in a value list.
ATTENDEE;RSVP=TRUE;ROLE=REQ-PARTICIPANT:MAILTO: ATTENDEE;RSVP=TRUE;ROLE=REQ-PARTICIPANT:MAILTO:
jsmith@host.com jsmith@host.com
RDATE;VALUE=DATE:19970304,19970504,19970704,19970904 RDATE;VALUE=DATE:19970304,19970504,19970704,19970904
5.5. Multiple Property 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 (US-ASCII decimal 44). Individual
property definitions should be consulted for determining whether a property definitions should be consulted for determining whether a
specific property allows multiple values and in which of these two specific property allows multiple values and in which of these two
forms. forms.
5.6. 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
[RFC 2045]. Inline binary contact SHOULD only be used in [RFC2045]. Inline binary contact SHOULD only be used in applications
applications whose special circumstances demand that an iCalendar whose special circumstances demand that an iCalendar object be
object be expressed as a single entity. A property containing inline expressed as a single entity. A property containing inline binary
binary content information MUST specify the "ENCODING" property content information MUST specify the "ENCODING" property parameter.
parameter. Binary content information placed external to the Binary content information placed external to the iCalendar object
iCalendar object MUST be referenced by a uniform resource identifier MUST be referenced by a uniform resource identifier (URI).
(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://xyz.com/public/quarterly-report.doc ATTACH:http://example.com/public/quarterly-report.doc
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=image/basic;ENCODING=BASE64;VALUE=BINARY: ATTACH;FMTTYPE=image/basic;ENCODING=BASE64;VALUE=BINARY:
MIICajCCAdOgAwIBAgICBEUwDQYJKoZIhvcNAQEEBQAwdzELMAkGA1U MIICajCCAdOgAwIBAgICBEUwDQYJKoZIhvcNAQEEBQAwdzELMAkGA1U
EBhMCVVMxLDAqBgNVBAoTI05ldHNjYXBlIENvbW11bmljYXRpb25zIE EBhMCVVMxLDAqBgNVBAoTI05ldHNjYXBlIENvbW11bmljYXRpb25zIE
[...remainder of "BASE64" encoded binary data...] <...remainder of "BASE64" encoded binary data...>
5.7. Property Parameter Syntax 3.1.4. Character Set
There is not a property parameter to declare the character set used
in a property value. The default character set for an iCalendar
object is UTF-8 as defined in [RFC2279].
The "charset" Content-Type parameter can be used in MIME transports
to specify any other IANA registered character set.
3.2. Property Parameters
A property can have attributes associated with it. These "property A property can have attributes associated with it. These "property
parameters" contain meta-information about the property or the parameters" contain meta-information about the property or the
property value. Property parameters are provided to specify such 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 data type property value, the language of a text property value, the data 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 (US-ASCII decimal
58), SEMICOLON (US-ASCII decimal 59) or COMMA (US-ASCII decimal 44) 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 DOUBLE-QUOTE (US-ASCII Property parameter values MUST NOT contain the DQUOTE (US-ASCII
decimal 22) character. The DOUBLE-QUOTE (US-ASCII decimal 22) decimal 22) character. The DQUOTE (US-ASCII decimal 22) character is
character is used as a delimiter for parameter values that contain used as a delimiter for parameter values that contain restricted
restricted characters or URI text. For example: characters or URI text. For example:
DESCRIPTION;ALTREP="http://www.wiz.org":The Fall'98 Wild Wizards DESCRIPTION;ALTREP="http://www.wiz.org":The Fall'98 Wild Wizards
Conference - - Las Vegas, NV, USA 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.
6. iCalendar Objects The general property parameters defined by this memo are defined by
the following notation:
parameter = 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
/ ianaparam
; Some other IANA registered iCalendar parameter.
/ xparam
; A non-standard, experimental parameter.
ianaparam = iana-token "=" param-value *("," param-value)
xparam = x-name "=" param-value *("," param-value)
3.2.1. Alternate Text Representation
Parameter Name: ALTREP
Purpose: To specify an alternate text representation for the property
value.
Format Definition: The property parameter is defined by the following
notation:
altrepparam = "ALTREP" "=" DQUOTE uri DQUOTE
Description: The parameter specifies a URI that points to an
alternate representation for a textual property value. A property
specifying this parameter MUST also include a value that reflects
the default representation of the text value. The individual URI
parameter values MUST each be specified in a quoted-string.
Example:
DESCRIPTION;ALTREP="CID:<part3.msg.970415T083000@host.com>":Project
XYZ Review Meeting will include the following agenda items: (a)
Market Overview, (b) Finances, (c) Project Management
The "ALTREP" property parameter value might point to a "text/html"
content portion.
Content-Type:text/html
Content-Id:<part3.msg.970415T083000@host.com>
<html><body>
<p><b>Project XYZ Review Meeting</b> will include the following
agenda items:<ol><li>Market
Overview</li><li>Finances</li><li>Project Management</li></ol></p>
</body></html>
3.2.2. Common Name
Parameter Name: CN
Purpose: To specify the common name to be associated with the
calendar user specified by the property.
Format Definition: The property parameter is defined by the following
notation:
cnparam = "CN" "=" param-value
Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. The parameter specifies the common name
to be associated with the calendar user specified by the property.
The parameter value is text. The parameter value can be used for
display text to be associated with the calendar address specified
by the property.
Example:
ORGANIZER;CN="John Smith":MAILTO:jsmith@host.com
3.2.3. Calendar User Type
Parameter Name: CUTYPE
Purpose: To specify the type of calendar user specified by the
property.
Format Definition: The property parameter is defined by the following
notation:
cutypeparam = "CUTYPE" "="
("INDIVIDUAL" ; An individual
/ "GROUP" ; A group of individuals
/ "RESOURCE" ; A physical resource
/ "ROOM" ; A room resource
/ "UNKNOWN" ; Otherwise not known
/ x-name ; Experimental type
/ iana-token) ; Other IANA registered
; type
; Default is INDIVIDUAL
Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. The parameter identifies the type of
calendar user specified by the property. If not specified on a
property that allows this parameter, the default is INDIVIDUAL.
Example:
ATTENDEE;CUTYPE=GROUP:MAILTO:ietf-calsch@imc.org
3.2.4. Delegators
Parameter Name: DELEGATED-FROM
Purpose: To specify the calendar users that have delegated their
participation to the calendar user specified by the property.
Format Definition: The property parameter is defined by the following
notation:
delfromparam = "DELEGATED-FROM" "=" DQUOTE cal-address DQUOTE
*("," DQUOTE cal-address DQUOTE)
Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. This parameter can be specified on a
property that has a value type of calendar address. This
parameter specifies those calendar users that have delegated their
participation in a group scheduled event or to-do to the calendar
user specified by the property. The value MUST be a MAILTO URI as
defined in [RFC1738]. The individual calendar address parameter
values MUST each be specified in a quoted-string.
Example:
ATTENDEE;DELEGATED-FROM="MAILTO:jsmith@host.com":MAILTO:
jdoe@host.com
3.2.5. Delegatees
Parameter Name: DELEGATED-TO
Purpose: To specify the calendar users to whom the calendar user
specified by the property has delegated participation.
Format Definition: The property parameter is defined by the following
notation:
deltoparam = "DELEGATED-TO" "=" DQUOTE cal-address DQUOTE
*("," DQUOTE cal-address DQUOTE)
Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. This parameter specifies those calendar
users whom have been delegated participation in a group scheduled
event or to-do by the calendar user specified by the property.
The value MUST be a MAILTO URI as defined in [RFC1738]. The
individual calendar address parameter values MUST each be
specified in a quoted-string.
Example:
ATTENDEE;DELEGATED-TO="MAILTO:jdoe@host.com","MAILTO:jqpublic@
host.com":MAILTO:jsmith@host.com
3.2.6. Directory Entry Reference
Parameter Name: DIR
Purpose: To specify reference to a directory entry associated with
the calendar user specified by the property.
Format Definition: The property parameter is defined by the following
notation:
dirparam = "DIR" "=" DQUOTE uri DQUOTE
Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. The parameter specifies a reference to
the directory entry associated with the calendar user specified by
the property. The parameter value is a URI. The individual URI
parameter values MUST each be specified in a quoted-string.
Example:
ORGANIZER;DIR="ldap://host.com:6666/o=eDABC%20Industries,c=3DUS??
(cn=3DBJim%20Dolittle)":MAILTO:jimdo@host1.com
3.2.7. Inline Encoding
Parameter Name: ENCODING
Purpose: To specify an alternate inline encoding for the property
value.
Format Definition: The property parameter is defined by the following
notation:
encodingparam = "ENCODING" "="
("8BIT"
; "8bit" text encoding is defined in [RFC2045]
/ "BASE64"
; "BASE64" binary encoding format is defined in [RFC2045]
/ iana-token
; Some other IANA registered iCalendar encoding type
/ x-name)
; A non-standard, experimental encoding type
Description: The property parameter identifies the inline encoding
used in a property value. The default encoding is "8BIT",
corresponding to a property value consisting of text. The
"BASE64" encoding type corresponds to a property value encoded
using the "BASE64" encoding defined in [RFC2045].
If the value type parameter is ";VALUE=BINARY", then the inline
encoding parameter MUST be specified with the value
";ENCODING=BASE64".
Example:
ATTACH;FMTYPE=IMAGE/JPEG;ENCODING=BASE64;VALUE=BINARY:MIICajC
CAdOgAwIBAgICBEUwDQYJKoZIhvcNAQEEBQAwdzELMAkGA1UEBhMCVVMxLDA
qBgNVBAoTI05ldHNjYXBlIENvbW11bmljYXRpb25zIENvcnBvcmF0aW9uMRw
<...remainder of "BASE64" encoded binary data...>
3.2.8. Format Type
Parameter Name: FMTTYPE
Purpose: To specify the content type of a referenced object.
Format Definition: The property parameter is defined by the following
notation:
fmttypeparam = "FMTTYPE" "=" iana-token
; A IANA registered content type
/ x-name
; A non-standard content type
Description: This parameter can be specified on properties that are
used to reference an object. The parameter specifies the content
type of the referenced object. For example, on the "ATTACH"
property, a FTP type URI value does not, by itself, necessarily
convey the type of content associated with the resource. The
parameter value MUST be the TEXT for either an IANA registered
content type or a non-standard content type.
Example:
ATTACH;FMTTYPE=application/msword:ftp://domain.com/pub/docs/
agenda.doc
3.2.9. Free/Busy Time Type
Parameter Name: FBTYPE
Purpose: To specify the free or busy time type.
Format Definition: The property parameter is defined by the following
notation:
fbtypeparam = "FBTYPE" "=" ("FREE" / "BUSY"
/ "BUSY-UNAVAILABLE" / "BUSY-TENTATIVE"
/ x-name
; Some experimental iCalendar data type.
/ iana-token)
; Some other IANA registered iCalendar data type.
Description: The parameter specifies the free or busy time type. The
value FREE indicates that the time interval is free for
scheduling. The value BUSY indicates that the time interval is
busy because one or more events have been scheduled for that
interval. The value BUSY-UNAVAILABLE indicates that the time
interval is busy and that the interval can not be scheduled. The
value BUSY-TENTATIVE indicates that the time interval is busy
because one or more events have been tentatively scheduled for
that interval. If not specified on a property that allows this
parameter, the default is BUSY.
Example: The following is an example of this parameter on a FREEBUSY
property.
FREEBUSY;FBTYPE=BUSY:19980415T133000Z/19980415T170000Z
3.2.10. Language
Parameter Name: LANGUAGE
Purpose: To specify the language for text values in a property or
property parameter.
Format Definition: The property parameter is defined by the following
notation:
languageparam = "LANGUAGE" "=" language
language = <Text identifying a language, as defined in [RFC1766]>
Description: This parameter can be specified on properties with a
text value type. The parameter identifies the language of the
text in the property or property parameter value. The value of
the "language" property parameter is that defined in [RFC1766].
For transport in a MIME entity, the Content-Language header field
can be used to set the default language for the entire body part.
Otherwise, no default language is assumed.
Example:
SUMMARY;LANGUAGE=us-EN:Company Holiday Party
LOCATION;LANGUAGE=en:Germany
LOCATION;LANGUAGE=no:Tyskland
The following example makes use of the Quoted-Printable encoding
in order to represent non-ASCII characters.
LOCATION;LANGUAGE=3Dda:K=C3=B8benhavn
LOCATION;LANGUAGE=en:Copenhagen
3.2.11. Group or List Membership
Parameter Name: MEMBER
Purpose: To specify the group or list membership of the calendar user
specified by the property.
Format Definition: The property parameter is defined by the following
notation:
memberparam = "MEMBER" "=" DQUOTE cal-address DQUOTE
*("," DQUOTE cal-address DQUOTE)
Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. The parameter identifies the groups or
list membership for the calendar user specified by the property.
The parameter value either a single calendar address in a quoted-
string or a COMMA character (US-ASCII decimal 44) list of calendar
addresses, each in a quoted-string. The individual calendar
address parameter values MUST each be specified in a quoted-
string.
Example:
ATTENDEE;MEMBER="MAILTO:ietf-calsch@imc.org":MAILTO:jsmith@host.com
ATTENDEE;MEMBER="MAILTO:projectA@host.com","MAILTO:projectB@host.
com":MAILTO:janedoe@host.com
3.2.12. Participation Status
Parameter Name: PARTSTAT
Purpose: To specify the participation status for the calendar user
specified by the property.
Format Definition: The property parameter is defined by the following
notation:
partstatparam = "PARTSTAT" "="
("NEEDS-ACTION" ; Event needs action
/ "ACCEPTED" ; Event accepted
/ "DECLINED" ; Event declined
/ "TENTATIVE" ; Event tentatively
; accepted
/ "DELEGATED" ; Event delegated
/ x-name ; Experimental status
/ iana-token) ; Other IANA registered
; status
; These are the participation statuses for a "VEVENT". Default is
; NEEDS-ACTION
partstatparam /= "PARTSTAT" "="
("NEEDS-ACTION" ; To-do needs action
/ "ACCEPTED" ; To-do accepted
/ "DECLINED" ; To-do declined
/ "TENTATIVE" ; To-do tentatively
; 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
partstatparam /= "PARTSTAT" "="
("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
CAL-ADDRESS value type. The parameter identifies the
participation status for the calendar user specified by the
property value. The parameter values differ depending on whether
they are associated with a group scheduled "VEVENT", "VTODO" or
"VJOURNAL". The values MUST match one of the values allowed for
the given calendar component. If not specified on a property that
allows this parameter, the default value is NEEDS-ACTION.
Example:
ATTENDEE;PARTSTAT=DECLINED:MAILTO:jsmith@host.com
3.2.13. Recurrence Identifier Range
Parameter Name: RANGE
Purpose: To specify the effective range of recurrence instances from
the instance specified by the recurrence identifier specified by
the property.
Format Definition: The property parameter is defined by the following
notation:
rangeparam = "RANGE" "=" ("THISANDPRIOR"
; To specify all instances prior to the recurrence identifier
/ "THISANDFUTURE")
; To specify the instance specified by the recurrence identifier
; and all subsequent recurrence instances
Description: The parameter can be specified on a property that
specifies a recurrence identifier. The parameter specifies the
effective range of recurrence instances that is specified by the
property. The effective range is from the recurrence identified
specified by the property. If this parameter is not specified an
allowed property, then the default range is the single instance
specified by the recurrence identifier value of the property. The
parameter value can be "THISANDPRIOR" to indicate a range defined
by the recurrence identified value of the property and all prior
instances. The parameter value can also be "THISANDFUTURE" to
indicate a range defined by the recurrence identifier and all
subsequent instances.
Example:
RECURRENCE-ID;RANGE=THISANDPRIOR:19980401T133000Z
3.2.14. Alarm Trigger Relationship
Parameter Name: RELATED
Purpose: To specify the relationship of the alarm trigger with
respect to the start or end of the calendar component.
Format Definition: The property parameter is defined by the following
notation:
trigrelparam = "RELATED" "="
("START" ; Trigger off of start
/ "END") ; Trigger off of end
Description: The parameter can be specified on properties that
specify an alarm trigger with a DURATION value type. The
parameter specifies whether the alarm will trigger relative to the
start or end of the calendar component. The parameter value START
will set the alarm to trigger off the start of the calendar
component; the parameter value END will set the alarm to trigger
off the end of the calendar component. If the parameter is not
specified on an allowable property, then the default is START.
Example:
TRIGGER;RELATED=END:PT5M
3.2.15. Relationship Type
Parameter Name: RELTYPE
Purpose: To specify the type of hierarchical relationship associated
with the calendar component specified by the property.
Format Definition: The property parameter is defined by the following
notation:
reltypeparam = "RELTYPE" "="
("PARENT" ; Parent relationship. Default.
/ "CHILD" ; Child relationship
/ "SIBLING ; Sibling relationship
/ iana-token ; Some other IANA registered
; iCalendar relationship type
/ x-name) ; A non-standard, experimental
; relationship type
Description: This parameter can be specified on a property that
references another related calendar. The parameter specifies the
hierarchical relationship type of the calendar component
referenced by the property. The parameter value can be PARENT, to
indicate that the referenced calendar component is a superior of
calendar component; CHILD to indicate that the referenced calendar
component is a subordinate of the calendar component; SIBLING to
indicate that the referenced calendar component is a peer of the
calendar component. If this parameter is not specified on an
allowable property, the default relationship type is PARENT.
Example:
RELATED-TO;RELTYPE=SIBLING:<19960401-080045-4000F192713@host.com>
3.2.16. Participation Role
Parameter Name: ROLE
Purpose: To specify the participation role for the calendar user
specified by the property.
Format Definition: The property parameter is defined by the following
notation:
roleparam = "ROLE" "="
("CHAIR" ; Indicates chair of the
; calendar entity
/ "REQ-PARTICIPANT" ; Indicates a participant whose
; participation is required
/ "OPT-PARTICIPANT" ; Indicates a participant whose
; participation is optional
/ "NON-PARTICIPANT" ; Indicates a participant who is
; copied for information
; purposes only
/ x-name ; Experimental role
/ iana-token) ; Other IANA role
; Default is REQ-PARTICIPANT
Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. The parameter specifies the participation
role for the calendar user specified by the property in the group
schedule calendar component. If not specified on a property that
allows this parameter, the default value is REQ-PARTICIPANT.
Example:
ATTENDEE;ROLE=CHAIR:MAILTO:mrbig@host.com
3.2.17. RSVP Expectation
Parameter Name: RSVP
Purpose: To specify whether there is an expectation of a favor of a
reply from the calendar user specified by the property value.
Format Definition: The property parameter is defined by the following
notation:
rsvpparam = "RSVP" "=" ("TRUE" / "FALSE")
; Default is FALSE
Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. The parameter identifies the expectation
of a reply from the calendar user specified by the property value.
This parameter is used by the "Organizer" to request a
participation status reply from an "Attendee" of a group scheduled
event or to-do. If not specified on a property that allows this
parameter, the default value is FALSE.
Example:
ATTENDEE;RSVP=TRUE:MAILTO:jsmith@host.com
3.2.18. Sent By
Parameter Name: SENT-BY
Purpose: To specify the calendar user that is acting on behalf of the
calendar user specified by the property.
Format Definition: The property parameter is defined by the following
notation:
sentbyparam = "SENT-BY" "=" DQUOTE cal-address DQUOTE
Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. The parameter specifies the calendar user
that is acting on behalf of the calendar user specified by the
property. The parameter value MUST be a MAILTO URI as defined in
[RFC1738]. The individual calendar address parameter values MUST
each be specified in a quoted-string.
Example:
ORGANIZER;SENT-BY:"MAILTO:sray@host.com":MAILTO:jsmith@host.com
3.2.19. Time Zone Identifier
Parameter Name: TZID
Purpose: To specify the identifier for the time zone definition for a
time component in the property value.
Format Definition: The property parameter is defined by the following
notation:
tzidparam = "TZID" "=" [tzidprefix] paramtext CRLF
tzidprefix = "/"
Description: The parameter MUST be specified on the "DTSTART",
"DTEND", "DUE", "EXDATE" and "RDATE" properties when either a
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
TIME value type definition for a description of UTC and "floating
time" formats. This property parameter specifies a text value
which uniquely identifies the "VTIMEZONE" calendar component to be
used when evaluating the time portion of the property. The value
of the TZID property parameter will be equal to the value of the
TZID property for the matching time zone definition. An
individual "VTIMEZONE" calendar component MUST be specified for
each unique "TZID" parameter value specified in the iCalendar
object.
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.
The presence of the SOLIDUS character (US-ASCII decimal 47) as a
prefix, indicates that this TZID represents a unique ID in a
globally defined time zone registry (when such registry is
defined).
Note: This document does not define a naming convention for
time zone identifiers. Implementers may want to use the naming
conventions defined in existing time zone specifications such
as the public-domain Olson database [TZDB]. The specification
of globally unique time zone identifiers is not addressed by
this document and is left for future study.
The following are examples of this property parameter:
DTSTART;TZID=US-Eastern:19980119T020000
DTEND;TZID=US-Eastern:19980119T030000
The TZID property parameter MUST NOT be applied to DATE-TIME or
TIME properties whose time values are specified in UTC.
The use of local time in a DATE-TIME or TIME value without the
TZID property parameter is to be interpreted as a local time
value, regardless of the existence of "VTIMEZONE" calendar
components in the iCalendar object.
For more information see the sections on the data types DATE-TIME
and TIME.
3.2.20. Value Data Types
Parameter Name: VALUE
Purpose: To explicitly specify the data type format for a property
value.
Format Definition: The property parameter is defined by the following
notation:
valuetypeparam = "VALUE" "=" valuetype
valuetype = ("BINARY"
/ "BOOLEAN"
/ "CAL-ADDRESS"
/ "DATE"
/ "DATE-TIME"
/ "DURATION"
/ "FLOAT"
/ "INTEGER"
/ "PERIOD"
/ "RECUR"
/ "TEXT"
/ "TIME"
/ "URI"
/ "UTC-OFFSET"
/ x-name
; Some experimental iCalendar data type.
/ iana-token)
; Some other IANA registered iCalendar data type.
Description: The parameter specifies the data type and format of the
property value. The property values MUST be of a single value
type. For example, a "RDATE" property cannot have a combination
of DATE- TIME and TIME value types.
If the property's value is the default value type, then this
parameter need not be specified. However, if the property's
default value type is overridden by some other allowable value
type, then this parameter MUST be specified.
3.3. Property Value Data Types
The properties in an iCalendar object are strongly typed. The
definition of each property restricts the value to be one of the
value data types, or simply value types, defined in this section.
The value type for a property will either be specified implicitly as
the default value type or will be explicitly specified with 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
"VALUE" parameter.
3.3.1. Binary
Value Name: BINARY
Purpose: This value type is used to identify properties that contain
a character encoding of inline binary data. For example, an
inline attachment of an object code might be included in an
iCalendar object.
Format Definition: The value type is defined by the following
notation:
binary = *(4b-char) [b-end]
; A "BASE64" encoded character string, as defined by [RFC2045].
b-end = (2b-char "==") / (3b-char "=")
b-char = ALPHA / DIGIT / "+" / "/"
Description: Property values with this value type MUST also include
the inline encoding parameter sequence of ";ENCODING=BASE64".
That is, all inline binary data MUST first be character encoded
using the "BASE64" encoding method defined in [RFC2045]. No
additional content value encoding (i.e., BACKSLASH character
encoding) is defined for this value type.
Example: The following is an abridged example of a "BASE64" encoded
binary value data.
ATTACH;VALUE=BINARY;ENCODING=BASE64:MIICajCCAdOgAwIBAgICBEUwDQY
JKoZIhvcNAQEEBQAwdzELMAkGA1UEBhMCVVMxLDAqBgNVBAoTI05ldHNjYXBlI
ENvbW11bmljYXRpb25zIENvcnBvcmF0aW9uMRwwGgYDVQQLExNJbmZv
<...remainder of "BASE64" encoded binary data...>
3.3.2. Boolean
Value Name: BOOLEAN
Purpose: This value type is used to identify properties that contain
either a "TRUE" or "FALSE" Boolean value.
Format Definition: The value type is defined by the following
notation:
boolean = "TRUE" / "FALSE"
Description: These values are case insensitive text. No additional
content value encoding (i.e., BACKSLASH character encoding) is
defined for this value type.
Example: The following is an example of a hypothetical property that
has a BOOLEAN value type:
GIBBERISH:TRUE
3.3.3. Calendar User Address
Value Name: CAL-ADDRESS
Purpose: This value type is used to identify properties that contain
a calendar user address.
Format Definition: The value type is defined by the following
notation:
cal-address = uri
Description: The value is a URI as defined by [RFC1738] or any other
IANA registered form for a URI. When used to address an Internet
email transport address for a calendar user, the value MUST be a
MAILTO URI, as defined by [RFC1738]. No additional content value
encoding (i.e., BACKSLASH character encoding) is defined for this
value type.
Example:
ATTENDEE:MAILTO:jane_doe@host.com
3.3.4. Date
Value Name: DATE
Purpose: This value type is used to identify values that contain a
calendar date.
Format Definition: The value type is defined by the following
notation:
date = date-value
date-value = date-fullyear date-month date-mday
date-fullyear = 4DIGIT
date-month = 2DIGIT ;01-12
date-mday = 2DIGIT ;01-28, 01-29, 01-30, 01-31
;based on month/year
Description: If the property permits, multiple "date" values are
specified as a COMMA character (US-ASCII decimal 44) separated
list of values. The format for the value type is expressed as the
[ISO.8601.1988] complete representation, basic format for a
calendar date. The textual format specifies a four-digit year,
two-digit month, and two-digit day of the month. There are no
separator characters between the year, month and day component
text.
No additional content value encoding (i.e., BACKSLASH character
encoding) is defined for this value type.
Example: The following represents July 14, 1997:
19970714
3.3.5. Date-Time
Value Name: DATE-TIME
Purpose: This value type is used to identify values that specify a
precise calendar date and time of day.
Format Definition: The value type is defined by the following
notation:
date-time = date "T" time ;As specified in the date and time
;value definitions
Description: If the property permits, multiple "date-time" values are
specified as a COMMA character (US-ASCII decimal 44) separated
list of values. No additional content value encoding (i.e.,
BACKSLASH character encoding) is defined for this value type.
The "DATE-TIME" data type is used to identify values that contain
a precise calendar date and time of day. The format is based on
the [ISO.8601.1988] complete representation, basic format for a
calendar date and time of day. The text format is a concatenation
of the "date", followed by the LATIN CAPITAL LETTER T character
(US-ASCII decimal 84) time designator, followed by the "time"
format.
The "DATE-TIME" data type expresses time values in three forms:
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:
DTSTART:19980119T230000-0800 ;Invalid time format
FORM #1: DATE WITH LOCAL TIME
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
zone. For example, the following represents Janurary 18, 1998, at
11 PM:
DTSTART:19980118T230000
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
represent the same hour, minute, and second value regardless of
which time zone is currently being observed. For example, an
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
the person is in. In these cases, a local time can be specified.
The recipient of an iCalendar object with a property value
consisting of a local time, without any relative time zone
information, SHOULD interpret the value as being fixed to whatever
time zone the ATTENDEE is in at any given moment. This means that
two ATTENDEEs, in different time zones, receiving the same event
definition as a floating time, may be participating in the event
at different actual times. Floating time SHOULD only be used
where that is the reasonable behavior.
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
time zone reference MUST be specified.
The use of local time in a DATE-TIME value without the TZID
property parameter is to be interpreted as floating time,
regardless of the existence of "VTIMEZONE" calendar components in
the iCalendar object.
FORM #2: DATE WITH UTC TIME
The date with UTC time, or absolute time, is identified by a LATIN
CAPITAL LETTER Z suffix character (US-ASCII decimal 90), the UTC
designator, appended to the time value. For example, the
following represents January 19, 1998, at 0700 UTC:
DTSTART:19980119T070000Z
The TZID property parameter MUST NOT be applied to DATE-TIME
properties whose time values are specified in UTC.
FORM #3: DATE WITH LOCAL TIME AND TIME ZONE REFERENCE
The date and local time with reference to time zone information is
identified by the use the TZID property parameter to reference the
appropriate time zone definition. TZID is discussed in detail in
the section on Time Zone. For example, the following represents 2
AM in New York on Janurary 19, 1998:
DTSTART;TZID=US-Eastern:19980119T020000
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"
property.
DTSTART:19970714T133000 ;Local time
DTSTART:19970714T173000Z ;UTC time
DTSTART;TZID=US-Eastern:19970714T133000 ;Local time and time
; zone reference
A time value MUST ONLY specify 60 seconds when specifying the
periodic "leap second" in the time value. For example:
COMPLETED:19970630T235960Z
3.3.6. Duration
Value Name: DURATION
Purpose: This value type is used to identify properties that contain
a duration of time.
Format Definition: The value type is defined by the following
notation:
dur-value = (["+"] / "-") "P" (dur-date / dur-time / dur-week)
dur-date = dur-day [dur-time]
dur-time = "T" (dur-hour / dur-minute / dur-second)
dur-week = 1*DIGIT "W"
dur-hour = 1*DIGIT "H" [dur-minute]
dur-minute = 1*DIGIT "M" [dur-second]
dur-second = 1*DIGIT "S"
dur-day = 1*DIGIT "D"
Description: If the property permits, multiple "duration" values are
specified by a COMMA character (US-ASCII decimal 44) separated
list of values. The format is expressed as the [ISO.8601.1988]
basic format for the duration of time. The format can represent
durations in terms of weeks, days, hours, minutes, and seconds.
No additional content value encoding (i.e., BACKSLASH character
encoding) are defined for this value type.
Example: A duration of 15 days, 5 hours and 20 seconds would be:
P15DT5H0M20S
A duration of 7 weeks would be:
P7W
3.3.7. Float
Value Name: FLOAT
Purpose: This value type is used to identify properties that contain
a real number value.
Format Definition: The value type is defined by the following
notation:
float = (["+"] / "-") 1*DIGIT ["." 1*DIGIT]
Description: If the property permits, multiple "float" values are
specified by a COMMA character (US-ASCII decimal 44) separated
list of values.
No additional content value encoding (i.e., BACKSLASH character
encoding) is defined for this value type.
Example:
1000000.0000001
1.333
-3.14
3.3.8. Integer
Value Name: INTEGER
Purpose: This value type is used to identify properties that contain
a signed integer value.
Format Definition: The value type is defined by the following
notation:
integer = (["+"] / "-") 1*DIGIT
Description: If the property permits, multiple "integer" values are
specified by a COMMA character (US-ASCII decimal 44) separated
list of values. The valid range for "integer" is -2147483648 to
2147483647. If the sign is not specified, then the value is
assumed to be positive.
No additional content value encoding (i.e., BACKSLASH character
encoding) is defined for this value type.
Example:
1234567890
-1234567890
+1234567890
432109876
3.3.9. Period of Time
Value Name: PERIOD
Purpose: This value type is used to identify values that contain a
precise period of time.
Format Definition: The value type is defined by the following
notation:
period = period-explicit / period-start
period-explicit = date-time "/" date-time
; [ISO.8601.1988] complete representation basic format for a
; period of time consisting of a start and end. The start MUST
; be before the end.
period-start = date-time "/" dur-value
; [ISO.8601.1988] complete representation basic format for a
; period of time consisting of a start and positive duration
; of time.
Description: If the property permits, multiple "period" values are
specified by a COMMA character (US-ASCII decimal 44) separated
list of values. There are two forms of a period of time. First,
a period of time is identified by its start and its end. This
format is expressed as the [ISO.8601.1988] complete
representation, basic format for "DATE-TIME" start of the period,
followed by a SOLIDUS character (US-ASCII decimal 47), followed by
the "DATE-TIME" of the end of the period. The start of the period
MUST be before the end of the period. Second, a period of time
can also be defined by a start and a positive duration of time.
The format is expressed as the [ISO.8601.1988] complete
representation, basic format for the "DATE-TIME" start of the
period, followed by a SOLIDUS character (US-ASCII decimal 47),
followed by the [ISO.8601.1988] basic format for "DURATION" of the
period.
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:
19970101T180000Z/19970102T070000Z
The period start at 18:00:00 on January 1, 1997 and lasting 5
hours and 30 minutes would be:
19970101T180000Z/PT5H30M
No additional content value encoding (i.e., BACKSLASH character
encoding) is defined for this value type.
3.3.10. Recurrence Rule
Value Name: RECUR
Purpose: This value type is used to identify properties that contain
a recurrence rule specification.
Format Definition: The value type is defined by the following
notation:
recur = "FREQ"=freq *(
; either UNTIL or COUNT may appear in a 'recur',
; but UNTIL and COUNT MUST NOT occur in the same 'recur'
( ";" "UNTIL" "=" enddate ) /
( ";" "COUNT" "=" 1*DIGIT ) /
; the rest of these keywords are optional,
; but MUST NOT occur more than once
( ";" "INTERVAL" "=" 1*DIGIT ) /
( ";" "BYSECOND" "=" byseclist ) /
( ";" "BYMINUTE" "=" byminlist ) /
( ";" "BYHOUR" "=" byhrlist ) /
( ";" "BYDAY" "=" bywdaylist ) /
( ";" "BYMONTHDAY" "=" bymodaylist ) /
( ";" "BYYEARDAY" "=" byyrdaylist ) /
( ";" "BYWEEKNO" "=" bywknolist ) /
( ";" "BYMONTH" "=" bymolist ) /
( ";" "BYSETPOS" "=" bysplist ) /
( ";" "WKST" "=" weekday ) /
( ";" x-name "=" text )
)
freq = "SECONDLY" / "MINUTELY" / "HOURLY" / "DAILY"
/ "WEEKLY" / "MONTHLY" / "YEARLY"
enddate = date
enddate =/ date-time ;An UTC value
byseclist = seconds / ( seconds *("," seconds) )
seconds = 1DIGIT / 2DIGIT ;0 to 59
byminlist = minutes / ( minutes *("," minutes) )
minutes = 1DIGIT / 2DIGIT ;0 to 59
byhrlist = hour / ( hour *("," hour) )
hour = 1DIGIT / 2DIGIT ;0 to 23
bywdaylist = weekdaynum / ( weekdaynum *("," weekdaynum) )
weekdaynum = [([plus] ordwk / minus ordwk)] weekday
plus = "+"
minus = "-"
ordwk = 1DIGIT / 2DIGIT ;1 to 53
weekday = "SU" / "MO" / "TU" / "WE" / "TH" / "FR" / "SA"
;Corresponding to SUNDAY, MONDAY, TUESDAY, WEDNESDAY, THURSDAY,
;FRIDAY, SATURDAY and SUNDAY days of the week.
bymodaylist = monthdaynum / ( monthdaynum *("," monthdaynum) )
monthdaynum = ([plus] ordmoday) / (minus ordmoday)
ordmoday = 1DIGIT / 2DIGIT ;1 to 31
byyrdaylist = yeardaynum / ( yeardaynum *("," yeardaynum) )
yeardaynum = ([plus] ordyrday) / (minus ordyrday)
ordyrday = 1DIGIT / 2DIGIT / 3DIGIT ;1 to 366
bywknolist = weeknum / ( weeknum *("," weeknum) )
weeknum = ([plus] ordwk) / (minus ordwk)
bymolist = monthnum / ( monthnum *("," monthnum) )
monthnum = 1DIGIT / 2DIGIT ;1 to 12
bysplist = setposday / ( setposday *("," setposday) )
setposday = yeardaynum
Description: If the property permits, multiple "recur" values are
specified by a COMMA character (US-ASCII decimal 44) separated
list of values. The value type is a structured value consisting
of a list of one or more recurrence grammar parts. Each rule part
is defined by a NAME=VALUE pair. The rule parts are separated
from each other by the SEMICOLON character (US-ASCII decimal 59).
The rule parts are not ordered in any particular sequence.
Individual rule parts MUST only be specified once.
The FREQ rule part identifies the type of recurrence rule. This
rule part MUST be specified in the recurrence rule. Valid values
include SECONDLY, to specify repeating events based on an interval
of a second or more; MINUTELY, to specify repeating events based
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
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;
MONTHLY, to specify repeating events based on an interval of a
month or more; and YEARLY, to specify repeating events based on an
interval of a year or more.
The INTERVAL rule part contains a positive integer representing
how often the recurrence rule repeats. The default value is "1",
meaning every second for a SECONDLY rule, or every minute 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
MONTHLY rule and every year for a YEARLY rule.
The UNTIL rule part defines a date-time value which bounds the
recurrence rule in an inclusive manner. If the value specified by
UNTIL is synchronized with the specified recurrence, this date or
date-time becomes the last instance of the recurrence. If
specified as a date-time value, then it MUST be specified in an
UTC time format. If not present, and the COUNT rule part is also
not present, the RRULE is considered to repeat forever.
The COUNT rule part defines the number of occurrences at which to
range-bound the recurrence. The "DTSTART" property value, if
specified, counts as the first occurrence.
The BYSECOND rule part specifies a COMMA character (US-ASCII
decimal 44) separated list of seconds within a minute. Valid
values are 0 to 59. The BYMINUTE rule part specifies a COMMA
character (US-ASCII decimal 44) separated list of minutes within
an hour. Valid values are 0 to 59. The BYHOUR rule part
specifies a COMMA character (US- ASCII decimal 44) separated list
of hours of the day. Valid values are 0 to 23.
The BYDAY rule part specifies a COMMA character (US-ASCII decimal
44) separated list of days of the week; MO indicates Monday; TU
indicates Tuesday; WE indicates Wednesday; TH indicates Thursday;
FR indicates Friday; SA indicates Saturday; SU indicates Sunday.
Each BYDAY value can also be preceded by a positive (+n) or
negative (-n) integer. If present, this indicates the nth
occurrence of the specific day within the MONTHLY or YEARLY RRULE.
For example, within a MONTHLY rule, +1MO (or simply 1MO)
represents the first Monday within the month, whereas -1MO
represents the last Monday of the month. If an integer modifier
is not present, it means all days of this type within the
specified frequency. For example, within a MONTHLY rule, MO
represents all Mondays within the month.
The BYMONTHDAY rule part specifies a COMMA character (ASCII
decimal 44) separated list of days of the month. Valid values are
1 to 31 or -31 to -1. For example, -10 represents the tenth to
the last day of the month.
The BYYEARDAY rule part specifies a COMMA character (US-ASCII
decimal 44) separated list of days of the year. Valid values are
1 to 366 or -366 to -1. For example, -1 represents the last day
of the year (December 31st) and -306 represents the 306th to the
last day of the year (March 1st).
The BYWEEKNO rule part specifies a COMMA character (US-ASCII
decimal 44) separated list of ordinals specifying weeks of the
year. Valid values are 1 to 53 or -53 to -1. This corresponds to
weeks according to week numbering as defined in [ISO.8601.1988].
A week is defined as a seven day period, starting on the day of
the week defined to be the week start (see WKST). Week number one
of the calendar year is the first week which contains at least
four (4) days in that calendar year. This rule part is only valid
for YEARLY rules. For example, 3 represents the third week of the
year.
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
January 1.
The BYMONTH rule part specifies a COMMA character (US-ASCII
decimal 44) separated list of months of the year. Valid values
are 1 to 12.
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
significant when a WEEKLY RRULE has an interval greater than 1,
and a BYDAY rule part is specified. This is also significant when
in a YEARLY RRULE when a BYWEEKNO rule part is specified. The
default value is MO.
The BYSETPOS rule part specifies a COMMA character (US-ASCII
decimal 44) separated list of values which corresponds to the nth
occurrence within the set of events specified by the rule. Valid
values are 1 to 366 or -366 to -1. It MUST only be used in
conjunction with another BYxxx rule part. For example "the last
work day of the month" could be represented as:
RRULE:FREQ=MONTHLY;BYDAY=MO,TU,WE,TH,FR;BYSETPOS=-1
Each BYSETPOS value can include a positive (+n) or negative (-n)
integer. If present, this indicates the nth occurrence of the
specific occurrence within the set of events specified by the
rule.
If BYxxx rule part values are found which are beyond the available
scope (ie, BYMONTHDAY=30 in February), they are simply ignored.
Information, not contained in the rule, necessary to determine the
various recurrence instance start time and dates are derived from
the Start Time (DTSTART) entry attribute. For example,
"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
specified for DTSTART.
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
frequency generally reduce or limit the number of occurrences of
the recurrence generated. For example, "FREQ=DAILY;BYMONTH=1"
reduces the number of recurrence instances from all days (if
BYMONTH tag is not present) to all days in January. BYxxx rule
parts for a period of time less than the frequency generally
increase or expand the number of occurrences of the recurrence.
For example, "FREQ=YEARLY;BYMONTH=1,2" increases the number of
days within the yearly recurrence set from 1 (if BYMONTH tag is
not present) to 2.
If multiple BYxxx rule parts are specified, then after evaluating
the specified FREQ and INTERVAL rule parts, the BYxxx rule parts
are applied to the current set of evaluated occurrences in the
following order: BYMONTH, BYWEEKNO, BYYEARDAY, BYMONTHDAY, BYDAY,
BYHOUR, BYMINUTE, BYSECOND and BYSETPOS; then COUNT and UNTIL are
evaluated.
Here is an example of evaluating multiple BYxxx rule parts.
DTSTART;TZID=US-Eastern:19970105T083000
RRULE:FREQ=YEARLY;INTERVAL=2;BYMONTH=1;BYDAY=SU;BYHOUR=8,9;
BYMINUTE=30
First, the "INTERVAL=2" would be applied to "FREQ=YEARLY" to
arrive at "every other year". Then, "BYMONTH=1" would be applied
to arrive at "every January, every other year". Then, "BYDAY=SU"
would be applied to arrive at "every Sunday in January, every
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".
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
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, every
other year". Similarly, if the BYMINUTE, BYHOUR, BYDAY,
BYMONTHDAY or BYMONTH rule part were missing, the appropriate
minute, hour, day or month would have been retrieved from the
"DTSTART" property.
No additional content value encoding (i.e., BACKSLASH character
encoding) is defined for this value type.
Example: The following is a rule which specifies 10 meetings which
occur every other day:
FREQ=DAILY;COUNT=10;INTERVAL=2
There are other examples specified in the "RRULE" specification.
3.3.11. Text
Value Name: TEXT
Purpose: This value type is used to identify values that contain
human readable text.
Format Definition: The character sets supported by this revision of
iCalendar are UTF-8 and US-ASCII thereof. The applicability to
other character sets is for future work. The value type is
defined by the following notation.
text = *(TSAFE-CHAR / ":" / DQUOTE / ESCAPED-CHAR)
; Folded according to description above
ESCAPED-CHAR = "\\" / "\;" / "\," / "\N" / "\n")
; \\ encodes \, \N or \n encodes newline
; \; encodes ;, \, encodes ,
TSAFE-CHAR = %x20-21 / %x23-2B / %x2D-39 / %x3C-5B
%x5D-7E / NON-US-ASCII
; Any character except CTLs not needed by the current
; character set, DQUOTE, ";", ":", "\", ","
Note: Certain other character sets may require modification of
the above definitions, but this is beyond the scope of this
document.
Description: If the property permits, multiple "text" values are
specified by a COMMA character (US-ASCII decimal 44) separated
list of values.
The language in which the text is represented can be controlled by
the "LANGUAGE" property parameter.
An intentional formatted text line break MUST only be included in
a "TEXT" property value by representing the line break with the
character sequence of BACKSLASH (US-ASCII decimal 92), followed by
a LATIN SMALL LETTER N (US-ASCII decimal 110) or a LATIN CAPITAL
LETTER N (US-ASCII decimal 78), that is "\n" or "\N".
The "TEXT" property values may also contain special characters
that are used to signify delimiters, such as a COMMA character for
lists of values or a SEMICOLON character for structured values.
In order to support the inclusion of these special characters in
"TEXT" property values, they MUST be escaped with a BACKSLASH
character. A BACKSLASH character (US-ASCII decimal 92) in a
"TEXT" property value MUST be escaped with another BACKSLASH
character. A COMMA character in a "TEXT" property value MUST be
escaped with a BACKSLASH character (US-ASCII decimal 92). A
SEMICOLON character in a "TEXT" property value MUST be escaped
with a BACKSLASH character (US-ASCII decimal 92). However, a
COLON character in a "TEXT" property value SHALL NOT be escaped
with a BACKSLASH character.
Example: A multiple line value of:
Project XYZ Final Review
Conference Room - 3B
Come Prepared.
would be represented as:
Project XYZ Final Review\nConference Room - 3B\nCome Prepared.
3.3.12. Time
Value Name: TIME
Purpose: This value type is used to identify values that contain a
time of day.
Format Definition: The data type is defined by the following
notation:
time = time-hour time-minute time-second [time-utc]
time-hour = 2DIGIT ;00-23
time-minute = 2DIGIT ;00-59
time-second = 2DIGIT ;00-60
;The "60" value is used to account for "leap" seconds.
time-utc = "Z"
Description: If the property permits, multiple "time" values are
specified by a COMMA character (US-ASCII decimal 44) separated
list of values. No additional content value encoding (i.e.,
BACKSLASH character encoding) is defined for this value type.
The "TIME" data type is used to identify values that contain a
time of day. The format is based on the [ISO.8601.1988] complete
representation, basic format for a time of day. The text format
consists of a two-digit 24-hour of the day (i.e., values 0-23),
two- digit minute in the hour (i.e., values 0-59), and two-digit
seconds in the minute (i.e., values 0-60). The seconds value of
60 MUST only to be used to account for "leap" seconds. Fractions
of a second are not supported by this format.
In parallel to the "DATE-TIME" definition above, the "TIME" data
type expresses time values in three forms:
The form of time with UTC offset MUST NOT be used. For example,
the following is NOT VALID for a time value:
230000-0800 ;Invalid time format
FORM #1 LOCAL TIME
The local time form is simply a time value that does not contain
the UTC designator nor does it reference a time zone. For
example, 11:00 PM:
230000
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
the same hour, minute, and second value regardless of which time
zone is currently being observed. For example, an 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 the person is
in. In these cases, a local time can be specified. The recipient
of an iCalendar object with a property value consisting of a local
time, without any relative time zone information, SHOULD interpret
the value as being fixed to whatever time zone the ATTENDEE is in
at any given moment. This means that two ATTENDEEs may
participate in the same event at different UTC times; floating
time SHOULD only be used where that is reasonable behavior.
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
time zone reference MUST be specified.
The use of local time in a TIME value without the TZID property
parameter is to be interpreted as a local time value, regardless
of the existence of "VTIMEZONE" calendar components in the
iCalendar object.
FORM #2: UTC TIME
UTC time, or absolute time, is identified by a LATIN CAPITAL
LETTER Z suffix character (US-ASCII decimal 90), the UTC
designator, appended to the time value. For example, the
following represents 07:00 AM UTC:
070000Z
The TZID property parameter MUST NOT be applied to TIME properties
whose time values are specified in UTC.
FORM #3: LOCAL TIME AND TIME ZONE REFERENCE
The local time with reference to time zone information form is
identified by the use the TZID property parameter to reference the
appropriate time zone definition. TZID is discussed in detail in
the section on Time Zone.
Example: The following represents 8:30 AM in New York in Winter, five
hours behind UTC, in each of the three formats using the "X-
TIMEOFDAY" non-standard property:
X-TIMEOFDAY:083000
X-TIMEOFDAY:133000Z
X-TIMEOFDAY;TZID=US-Eastern:083000
3.3.13. URI
Value Name: URI
Purpose: This value type is used to identify values that contain a
uniform resource identifier (URI) type of reference to the
property value.
Format Definition: The data type is defined by the following
notation:
uri = <As defined by any IETF RFC>
Description: This data type might be used to reference binary
information, for values that are large, or otherwise undesirable
to include directly in the iCalendar object.
The URI value formats in RFC 1738, RFC 2111 and any other IETF
registered value format can be specified.
Any IANA registered URI format can be used. These include, but
are not limited to, those defined in RFC 1738 and RFC 2111.
When a property parameter value is a URI value type, the URI MUST
be specified as a quoted-string value.
No additional content value encoding (i.e., BACKSLASH character
encoding) is defined for this value type.
Example: The following is a URI for a network file:
http://host1.com/my-report.txt
3.3.14. UTC Offset
Value Name: UTC-OFFSET
Purpose: This value type is used to identify properties that contain
an offset from UTC to local time.
Format Definition: The data type is defined by the following
notation:
utc-offset = time-numzone ;As defined above in time data type
time-numzone = ("+" / "-") time-hour time-minute [time-
second]
Description: The PLUS SIGN character MUST be specified for positive
UTC offsets (i.e., ahead of UTC). The MINUS SIGN character MUST
be specified for negative UTC offsets (i.e., behind of UTC). The
value of "-0000" and "-000000" are not allowed. The time-second,
if present, may not be 60; if absent, it defaults to zero.
No additional content value encoding (i.e., BACKSLASH character
encoding) is defined for this value type.
Example: The following UTC offsets are given for standard time for
New York (five hours behind UTC) and Geneva (one hour ahead of
UTC):
-0500
+0100
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 a single iCalendar object. However, multiple will consist of a single iCalendar object. However, multiple
iCalendar objects can be sequentially grouped together. The first iCalendar objects can be sequentially grouped together. The first
line and last line of the iCalendar object MUST contain a pair of line and last line of the iCalendar object MUST contain a pair of
iCalendar object delimiter strings. iCalendar object delimiter strings. The syntax for an iCalendar
object is as follows:
The syntax for an iCalendar object is as follows:
icalobject = 1*("BEGIN" ":" "VCALENDAR" CRLF icalobject = 1*("BEGIN" ":" "VCALENDAR" CRLF
icalbody icalbody
"END" ":" "VCALENDAR" CRLF) "END" ":" "VCALENDAR" CRLF)
Figure 8
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
DTSTART:19970714T170000Z DTSTART:19970714T170000Z
DTEND:19970715T035959Z DTEND:19970715T035959Z
SUMMARY:Bastille Day Party SUMMARY:Bastille Day Party
END:VEVENT END:VEVENT
END:VCALENDAR END:VCALENDAR
Figure 9 3.5. Property
7. Calendar Components A property is the definition of an individual attribute describing a
calendar or a calendar component. A property takes the form defined
by the "contentline" notation defined in Section 3.1.
The body of an iCalendar object consists of a sequence of calendar The following is an example of a property:
DTSTART:19960415T133000Z
This memo imposes no ordering of properties within an iCalendar
object.
Property names, parameter names and enumerated parameter values are
case insensitive. For example, the property name "DUE" is the same
as "due" and "Due", DTSTART;TZID=US-Eastern:19980714T120000 is the
same as DtStart;TzID=US-Eastern:19980714T120000.
3.6. Calendar Components
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 as a whole. The properties are attributes that apply to the calendar as a whole. The
calendar components are collections of properties that express a calendar components are collections of properties that express a
particular calendar semantic. For example, the calendar component particular calendar semantic. For example, the calendar component
can specify an event, a to-do, a journal entry, time zone can specify an event, a to-do, a journal entry, time zone
information, or free/busy time information, or an alarm. information, or 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:
skipping to change at page 19, line 4 skipping to change at page 49, line 37
1*contentline 1*contentline
"END" ":" iana-token CRLF "END" ":" iana-token CRLF
x-comp = "BEGIN" ":" x-name CRLF x-comp = "BEGIN" ":" x-name CRLF
1*contentline 1*contentline
"END" ":" x-name CRLF "END" ":" x-name CRLF
Figure 10
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 is possible information. In addition, a complex iCalendar object is possible
that is used to capture a complete snapshot of the contents of a that is used to capture a complete snapshot of the contents of a
calendar (e.g., composite of many different calendar components). calendar (e.g., composite of many different calendar components).
More commonly, an iCalendar object will consist of just a single More commonly, an iCalendar object will consist of just a single
"VEVENT", "VTODO" or "VJOURNAL" calendar component. "VEVENT", "VTODO" or "VJOURNAL" calendar component.
7.1. 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.
Formal 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 optional, ; the following are optional,
; but MUST NOT occur more than once ; but MUST NOT occur more than once
skipping to change at page 20, line 38 skipping to change at page 50, line 41
; 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 / exdate / exrule / rstatus / related / contact / exdate / exrule / rstatus / related /
resources / rdate / rrule / x-prop resources / rdate / rrule / x-prop
) )
Figure 11
Description: A "VEVENT" calendar component is a grouping of component Description: A "VEVENT" calendar component is a grouping of component
properties, and possibly including "VALARM" calendar components, that properties, and possibly including "VALARM" calendar components,
represents a scheduled amount of time on a calendar. For example, it that represents a scheduled amount of time on a calendar. For
can be an activity; such as a one-hour long, department meeting from example, it can be an activity; such as a one-hour long,
8:00 AM to 9:00 AM, tomorrow. Generally, an event will take up time department meeting from 8:00 AM to 9:00 AM, tomorrow. Generally,
on an individual calendar. Hence, the event will appear as an opaque an event will take up time on an individual calendar. Hence, the
interval in a search for busy time. Alternately, the event can have event will appear as an opaque interval in a search for busy time.
its Time Transparency set to "TRANSPARENT" in order to prevent Alternately, the event can have its Time Transparency set to
blocking of the event in searches for busy time. "TRANSPARENT" in order to prevent blocking of the event in
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 have a anniversary or daily reminder within a calendar. These events
DATE value type for the "DTSTART" property instead of the default have a DATE value type for the "DTSTART" property instead of the
data type of DATE-TIME. If such a "VEVENT" has a "DTEND" property, default data type of DATE-TIME. If such a "VEVENT" has a "DTEND"
it MUST be specified as a DATE value also. The anniversary type of property, it MUST be specified as a DATE value also. The
"VEVENT" can span more than one date (i.e, "DTEND" property value is anniversary type of "VEVENT" can span more than one date (i.e,
set to a calendar date after the "DTSTART" property value). "DTEND" property value is set to a calendar date after the
"DTSTART" property value).
The "DTSTART" property for a "VEVENT" specifies the inclusive start The "DTSTART" property for a "VEVENT" specifies the inclusive
of the event. For recurring events, it also specifies the very first start of the event. For recurring events, it also specifies the
instance in the recurrence set. The "DTEND" property for a "VEVENT" very first instance in the recurrence set. The "DTEND" property
calendar component specifies the non-inclusive end of the event. For for a "VEVENT" calendar component specifies the non-inclusive end
cases where a "VEVENT" calendar component specifies a "DTSTART" of the event. For cases where a "VEVENT" calendar component
property with a DATE data type but no "DTEND" property, the events specifies a "DTSTART" property with a DATE data type but no
non-inclusive end is the end of the calendar date specified by the "DTEND" property, the events non-inclusive end is the end of the
"DTSTART" property. For cases where a "VEVENT" calendar component calendar date specified by the "DTSTART" property. For cases
specifies a "DTSTART" property with a DATE-TIME data type but no where a "VEVENT" calendar component specifies a "DTSTART" property
"DTEND" property, the event ends on the same calendar date and time with a DATE-TIME data type but no "DTEND" property, the event ends
of day specified by the "DTSTART" property. on the same calendar date and time of day specified by the
"DTSTART" property.
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 1: 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@host.com UID:19970901T130000Z-123401@host.com
DTSTAMP:19970901T1300Z 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
Figure 12 The following is an example of the "VEVENT" calendar component
Example 2: The following is an example of the "VEVENT" calendar used to represent a reminder that will not be opaque, but rather
component used to represent a reminder that will not be opaque, but transparent, to searches for busy time:
rather transparent, to searches for busy time:
BEGIN:VEVENT BEGIN:VEVENT
UID:19970901T130000Z-123402@host.com UID:19970901T130000Z-123402@host.com
DTSTAMP:19970901T1300Z DTSTAMP:19970901T130000Z
DTSTART:19970401T163000Z DTSTART:19970401T163000Z
DTEND:19970402T010000Z DTEND:19970402T010000Z
SUMMARY:Laurel is in sensitivity awareness class. SUMMARY:Laurel is in sensitivity awareness class.
CLASS:PUBLIC CLASS:PUBLIC
CATEGORIES:BUSINESS,HUMAN RESOURCES CATEGORIES:BUSINESS,HUMAN RESOURCES
TRANSP:TRANSPARENT TRANSP:TRANSPARENT
END:VEVENT END:VEVENT
Figure 13 The following is an example of the "VEVENT" calendar component
used to represent an anniversary that will occur annually. Since
Example 3: The following is an example of the "VEVENT" calendar it takes up no time, it will not appear as opaque in a search for
component used to represent an anniversary that will occur annually. busy time; no matter what the value of the "TRANSP" property
Since it takes up no time, it will not appear as opaque in a search
for busy time; no matter what the value of the "TRANSP" property
indicates: indicates:
BEGIN:VEVENT BEGIN:VEVENT
UID:19970901T130000Z-123403@host.com UID:19970901T130000Z-123403@host.com
DTSTAMP:19970901T1300Z DTSTAMP:19970901T130000Z
DTSTART:19971102 DTSTART:19971102
SUMMARY:Our Blissful Anniversary SUMMARY:Our Blissful Anniversary
CLASS:CONFIDENTIAL CLASS:CONFIDENTIAL
CATEGORIES:ANNIVERSARY,PERSONAL,SPECIAL OCCASION CATEGORIES:ANNIVERSARY,PERSONAL,SPECIAL OCCASION
RRULE:FREQ=YEARLY RRULE:FREQ=YEARLY
END:VEVENT END:VEVENT
Figure 14 3.6.2. To-do Component
7.2. 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.
Formal 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 optional, ; the following are optional,
; but MUST NOT occur more than once ; but MUST NOT occur more than once
skipping to change at page 23, line 36 skipping to change at page 53, line 33
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 / exrule / rstatus / related / resources / exdate / exrule / rstatus / related / resources /
rdate / rrule / x-prop rdate / rrule / x-prop
) )
Figure 15
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 represent properties and possibly "VALARM" calendar components that
an action-item or assignment. For example, it can be used to represent an action-item or assignment. For example, it can be
represent an item of work assigned to an individual; such as "turn in used to represent an item of work assigned to an individual; such
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 "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.
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 with "DURATION") properties specifies a to-do that will be associated
each successive calendar date, until it is completed. with each successive calendar date, until it is completed.
Example: The following is an example of a "VTODO" calendar component: Example: The following is an example of a "VTODO" calendar component:
BEGIN:VTODO BEGIN:VTODO
UID:19970901T130000Z-123404@host.com UID:19970901T130000Z-123404@host.com
DTSTAMP:19970901T1300Z DTSTAMP:19970901T130000Z
DTSTART:19970415T133000Z DTSTART:19970415T133000Z
DUE:19970416T045959Z DUE:19970416T045959Z
SUMMARY:1996 Income Tax Preparation SUMMARY:1996 Income Tax Preparation
CLASS:CONFIDENTIAL CLASS:CONFIDENTIAL
CATEGORIES:FAMILY,FINANCE CATEGORIES:FAMILY,FINANCE
PRIORITY:1 PRIORITY:1
STATUS:NEEDS-ACTION STATUS:NEEDS-ACTION
END:VTODO END:VTODO
Figure 16 3.6.3. Journal Component
7.3. 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.
Formal 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 optional, ; the following are optional,
; but MUST NOT occur more than once ; but MUST NOT occur more than once
skipping to change at page 25, line 27 skipping to change at page 54, line 46
class / created / description / dtstart / dtstamp / class / created / description / dtstart / dtstamp /
last-mod / organizer / recurid / seq / status / last-mod / organizer / recurid / seq / status /
summary / uid / url / summary / uid / url /
; 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 / exdate / exrule / related / rdate / contact / exdate / exrule / related / rdate /
rrule / rstatus / x-prop rrule / rstatus / x-prop
) )
Figure 17
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 entry property is used to specify the calendar date that the journal
is associated with. Generally, it will have a DATE value data type, entry is associated with. Generally, it will have a DATE value
but it can also be used to specify a DATE-TIME value data type. data type, but it can also be used to specify a DATE-TIME value
Examples of a journal entry include a daily record of a legislative data type. Examples of a journal entry include a daily record of
body or a journal entry of individual telephone contacts for the day a legislative body or a journal entry of individual telephone
or an ordered list of accomplishments for the day. The "VJOURNAL" contacts for the day or an ordered list of accomplishments for the
calendar component can also be used to associate a document with a day. The "VJOURNAL" calendar component can also be used to
calendar date. associate a document with a calendar date.
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 be calendar component. However, "VJOURNAL" calendar components can
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@host.com UID:19970901T130000Z-123405@host.com
DTSTAMP:19970901T1300Z 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\, Lisa
and Bob. Aurora project plans were reviewed. There is currently and Bob. Aurora project plans were reviewed. There is currently
no budget reserves for this project. Lisa will escalate to no budget reserves for this project. Lisa will escalate to
management. Next meeting on Tuesday.\n management. Next meeting on Tuesday.\n
2. Telephone Conference: ABC Corp. sales representative called 2. Telephone Conference: ABC Corp. sales representative called
to discuss new printer. Promised to get us a demo by Friday.\n to discuss new printer. Promised to get us a demo by Friday.\n
3. Henry Miller (Handsoff Insurance): Car was totaled by tree. 3. Henry Miller (Handsoff Insurance): Car was totaled by tree.
Is looking into a loaner car. 654-2323 (tel). Is looking into a loaner car. 654-2323 (tel).
END:VJOURNAL END:VJOURNAL
Figure 18 3.6.4. Free/Busy Component
7.4. 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 request either a request for free/busy time, describe a response to a
for free/busy time or describe a published set of busy time. request for free/busy time or describe a published set of busy
time.
Formal Definition: A "VFREEBUSY" calendar component is defined by the Format Definition: A "VFREEBUSY" calendar component is defined by the
following notation: following notation:
freebusyc = "BEGIN" ":" "VFREEBUSY" CRLF freebusyc = "BEGIN" ":" "VFREEBUSY" CRLF
fbprop fbprop
"END" ":" "VFREEBUSY" CRLF "END" ":" "VFREEBUSY" CRLF
fbprop = *( fbprop = *(
; the following are optional, ; the following are optional,
; but MUST NOT occur more than once ; but MUST NOT occur more than once
skipping to change at page 27, line 24 skipping to change at page 56, line 21
; the following are optional, ; the following are optional,
; but MUST NOT occur more than once ; but MUST NOT occur more than once
contact / dtstart / dtend / duration / dtstamp / contact / dtstart / dtend / duration / dtstamp /
organizer / uid / url / organizer / uid / url /
; the following are optional, ; the following are optional,
; and MAY occur more than once ; and MAY occur more than once
attendee / comment / freebusy / rstatus / x-prop attendee / comment / freebusy / rstatus / x-prop
) )
Figure 19
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 to component properties that represents either a request for, a reply
a request for free or busy time information or a published set of to a request for free or busy time information or a published set
busy time information. 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 being property specifies the calendar users whose free/busy time is
requested; the "ORGANIZER" property specifies the calendar user who being requested; the "ORGANIZER" property specifies the calendar
is requesting the free/busy time; the "DTSTART" and "DTEND" user who is requesting the free/busy time; the "DTSTART" and
properties specify the window of time for which the free/busy time is "DTEND" properties specify the window of time for which the free/
being requested; the "UID" and "DTSTAMP" properties are specified to busy time is being requested; the "UID" and "DTSTAMP" properties
assist in proper sequencing of multiple free/busy time requests. are specified to assist in proper sequencing of multiple free/busy
time requests.
When used to reply to a request for free/busy time, the "ATTENDEE" When used to reply to a request for free/busy time, the "ATTENDEE"
property specifies the calendar user responding to the free/busy time property specifies the calendar user responding to the free/busy
request; the "ORGANIZER" property specifies the calendar user that time request; the "ORGANIZER" property specifies the calendar user
originally requested the free/busy time; the "FREEBUSY" property that originally requested the free/busy time; the "FREEBUSY"
specifies the free/busy time information (if it exists); and the property specifies the free/busy time information (if it exists);
and the "UID" and "DTSTAMP" properties are specified to assist in
"UID" and "DTSTAMP" properties are specified to assist in proper proper sequencing of multiple free/busy time replies.
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 created. property specifies the date/time that iCalendar object was
created.
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 be calendar component. Multiple "VFREEBUSY" calendar components can
specified within an iCalendar object. This permits the grouping of be specified within an iCalendar object. This permits the
Free/Busy information into logical collections, such as monthly grouping of Free/Busy information into logical collections, such
groups of busy time information. as monthly groups of busy time information.
The "VFREEBUSY" calendar component is intended for use in iCalendar The "VFREEBUSY" calendar component is intended for use in
object methods involving requests for free time, requests for busy iCalendar object methods involving requests for free time,
time, requests for both free and busy, and the associated replies. requests for busy time, requests for both free and busy, and the
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. One This property provides a terse representation of time periods.
or more "FREEBUSY" properties can be specified in the "VFREEBUSY" One or more "FREEBUSY" properties can be specified in the
calendar component. "VFREEBUSY" calendar component.
When present in a "VFREEBUSY" calendar component, the "DTSTART" and When present in a "VFREEBUSY" calendar component, the "DTSTART"
"DTEND" properties SHOULD be specified prior to any "FREEBUSY" and "DTEND" properties SHOULD be specified prior to any "FREEBUSY"
properties. In a free time request, these properties can be used in properties. In a free time request, these properties can be used
combination with the "DURATION" property to represent a request for a in combination with the "DURATION" property to represent a request
duration of free time within a specified window of time. for a duration of free time within a specified window of time.
The recurrence properties ("RRULE", "EXRULE", "RDATE", "EXDATE") are The recurrence properties ("RRULE", "EXRULE", "RDATE", "EXDATE")
not permitted within a "VFREEBUSY" calendar component. Any recurring are not permitted within a "VFREEBUSY" calendar component. Any
events are resolved into their individual busy time periods using the recurring events are resolved into their individual busy time
"FREEBUSY" property. periods using the "FREEBUSY" property.
Example 1: 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
ORGANIZER:MAILTO:jane_doe@host1.com ORGANIZER:MAILTO:jane_doe@host1.com
ATTENDEE:MAILTO:john_public@host2.com ATTENDEE:MAILTO:john_public@host2.com
DTSTART:19971015T050000Z DTSTART:19971015T050000Z
DTEND:19971016T050000Z DTEND:19971016T050000Z
DTSTAMP:19970901T083000Z DTSTAMP:19970901T083000Z
END:VFREEBUSY END:VFREEBUSY
Figure 20 The following is an example of a "VFREEBUSY" calendar component
Example 2: A "VFREEBUSY" calendar component used to reply to the used to reply to the request with busy time information:
request with busy time information.
BEGIN:VFREEBUSY BEGIN:VFREEBUSY
ORGANIZER:MAILTO:jane_doe@host1.com ORGANIZER:MAILTO:jane_doe@host1.com
ATTENDEE:MAILTO:john_public@host2.com ATTENDEE:MAILTO:john_public@host2.com
DTSTAMP:19970901T100000Z DTSTAMP:19970901T100000Z
FREEBUSY;VALUE=PERIOD:19971015T050000Z/PT8H30M, FREEBUSY;VALUE=PERIOD:19971015T050000Z/PT8H30M,
19971015T160000Z/PT5H30M,19971015T223000Z/PT6H30M 19971015T160000Z/PT5H30M,19971015T223000Z/PT6H30M
URL:http://host2.com/pub/busy/jpublic-01.ifb URL:http://host2.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
Figure 21 The following is an example of a "VFREEBUSY" calendar component
used to publish busy time information.
Example 3: a "VFREEBUSY" calendar component used to publish busy time
information.
BEGIN:VFREEBUSY BEGIN:VFREEBUSY
ORGANIZER:jsmith@host.com ORGANIZER:jsmith@host.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.host.com/calendar/busytime/jsmith.ifb URL:http://www.host.com/calendar/busytime/jsmith.ifb
END:VFREEBUSY END:VFREEBUSY
Figure 22 3.6.5. Time Zone Component
7.5. 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.
Formal Definition: A "VTIMEZONE" calendar component is defined by the Format Definition: A "VTIMEZONE" calendar component is defined by the
following notation: following notation:
timezonec = "BEGIN" ":" "VTIMEZONE" CRLF timezonec = "BEGIN" ":" "VTIMEZONE" CRLF
2*( 2*(
; '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, ; 'last-mod' and 'tzurl' are optional,
but MUST NOT occur more than once but MUST NOT occur more than once
last-mod / tzurl / last-mod / tzurl /
; one of 'standardc' or 'daylightc' MUST occur ; one of 'standardc' or 'daylightc' MUST occur
..; and each MAY occur more than once. ; and each MAY occur more than once.
standardc / daylightc / standardc / daylightc /
; the following is optional, ; the following is optional,
; and MAY occur more than once ; and MAY occur more than once
x-prop x-prop
) )
skipping to change at page 31, line 4 skipping to change at page 59, line 43
; but MUST NOT occur more than once ; but MUST NOT occur more than once
dtstart / tzoffsetto / tzoffsetfrom / dtstart / tzoffsetto / tzoffsetfrom /
; the following are optional, ; the following are optional,
; and MAY occur more than once ; and MAY occur more than once
comment / rdate / rrule / tzname / x-prop comment / rdate / rrule / tzname / x-prop
) )
Figure 23
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 offset geographic area. These rules describe at a minimum the base
from UTC for the time zone, often referred to as the Standard Time offset from UTC for the time zone, often referred to as the
offset. Many locations adjust their Standard Time forward or Standard Time offset. Many locations adjust their Standard Time
backward by one hour, in order to accommodate seasonal changes in forward or backward by one hour, in order to accommodate seasonal
number of daylight hours, often referred to as Daylight Saving Time. changes in number of daylight hours, often referred to as Daylight
Some locations adjust their time by a fraction of an hour. Standard Saving Time. Some locations adjust their time by a fraction of an
Time is also known as Winter Time. Daylight Saving Time is also hour. Standard Time is also known as Winter Time. Daylight
known as Advanced Time, Summer Time, or Legal Time in certain Saving Time is also known as Advanced Time, Summer Time, or Legal
countries. The following table shows the changes in time zone rules Time in certain countries. The following table shows the changes
in effect for New York City starting from 1967. Each line represents in time zone rules in effect for New York City starting from 1967.
a description or rule for a particular observance. Each line represents a description or rule for a particular
observance.
Effective Observance Rule Effective Observance Rule
+-----------+-------------------------+--------+--------------+ +-----------+-------------------------+--------+--------------+
| Date | (Date/Time) | Offset | Abbreviation | | Date | (Date/Time) | Offset | Abbreviation |
+-----------+-------------------------+--------+--------------+ +-----------+-------------------------+--------+--------------+
| 1967-* | last Sun in Oct, 02:00 | -0500 | EST | | 1967-* | last Sun in Oct, 02:00 | -0500 | EST |
| | | | |
| 1967-1973 | last Sun in Apr, 02:00 | -0400 | EDT | | 1967-1973 | last Sun in Apr, 02:00 | -0400 | EDT |
| | | | |
| 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-* | first Sun in Apr, 02:00 | -0400 | EDT | | 1987-* | first Sun in Apr, 02:00 | -0400 | EDT |
+-----------+-------------------------+--------+--------------+ +-----------+-------------------------+--------+--------------+
Effective Observance Rule
Date (Date/Time) Offset Abbreviation
1967-* last Sun in Oct, 02:00 -0500 EST
1967-1973 last Sun in Apr, 02:00 -0400 EDT
1974-1974 Jan 6, 02:00 -0400 EDT
1975-1975 Feb 23, 02:00 -0400 EDT
1976-1986 last Sun in Apr, 02:00 -0400 EDT
1987-* first Sun in Apr, 02:00 -0400 EDT
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. However, addressed by this document and is left for future study.
implementers may find the Olson time zone database [TZ] a useful However, implementers may find the Olson time zone database
reference. It is an informal, public-domain collection of time zone [TZDB] a useful reference. It is an informal, public-domain
information, which is currently being maintained by volunteer collection of time zone information, which is currently being
Internet participants, and is used in several operating systems. maintained by volunteer Internet participants, and is used in
This database contains current and historical time zone information several operating systems. This database contains current and
for a wide variety of locations around the globe; it provides a time historical time zone information for a wide variety of
zone identifier for every unique time zone rule set in actual use locations around the globe; it provides a time zone identifier
since 1970, with historical data going back to the introduction of for every unique time zone rule set in actual use since 1970,
standard time. with historical data going back to the introduction of standard
time.
Interoperability between two calendaring and scheduling applications, Interoperability between two calendaring and scheduling
especially for recurring events, to-dos or journal entries, is applications, especially for recurring events, to-dos or journal
dependent on the ability to capture and convey date and time entries, is dependent on the ability to capture and convey date
information in an unambiguous format. The specification of current and time information in an unambiguous format. The specification
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 a Standard Time and Daylight Saving Time observances (or rules) for
particular time zone for a given interval of time. The "VTIMEZONE" a particular time zone for a given interval of time. The
calendar component cannot be nested within other calendar components. "VTIMEZONE" calendar component cannot be nested within other
Multiple "VTIMEZONE" calendar components can exist in an iCalendar calendar components. Multiple "VTIMEZONE" calendar components can
object. In this situation, each "VTIMEZONE" MUST represent a unique exist in an iCalendar object. In this situation, each "VTIMEZONE"
time zone definition. This is necessary for some classes of events, MUST represent a unique time zone definition. This is necessary
such as airline flights, that start in one time zone and end in for some classes of events, such as airline flights, that start in
another. one time zone and end in another.
The "VTIMEZONE" calendar component MUST be present if the iCalendar The "VTIMEZONE" calendar component MUST be present if the
object contains an RRULE that generates dates on both sides of a time iCalendar object contains an RRULE that generates dates on both
zone shift (e.g. both in Standard Time and Daylight Saving Time) sides of a time zone shift (e.g., both in Standard Time and
unless the iCalendar object intends to convey a floating time (See Daylight Saving Time) unless the iCalendar object intends to
Section 13.13 for proper interpretation of floating time). It can be convey a floating time ( see Section 3.3.12 for proper
present if the iCalendar object does not contain such a RRULE. In interpretation of floating time). It can be present if the
addition, if a RRULE is present, there MUST be valid time zone iCalendar object does not contain such a RRULE. In addition, if a
information for all recurrence instances. RRULE is present, there MUST be valid time zone information for
all recurrence instances.
The "VTIMEZONE" calendar component MUST include the "TZID" property The "VTIMEZONE" calendar component MUST include the "TZID"
and at least one definition of a standard or daylight component. The property and at least one definition of a standard or daylight
standard or daylight component MUST include the "DTSTART", component. The standard or daylight component MUST include the
"TZOFFSETFROM" and "TZOFFSETTO" properties. "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 object. each unique "TZID" parameter value specified in the iCalendar
object.
Each "VTIMEZONE" calendar component consists of a collection of one Each "VTIMEZONE" calendar component consists of a collection of
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 collection observance). The "STANDARD" sub-component consists of a
of properties that describe Standard Time. The "DAYLIGHT" sub- collection of properties that describe Standard Time. The
component consists of a collection of properties that describe "DAYLIGHT" sub-component consists of a collection of properties
Daylight Saving Time. In general this collection of properties that describe Daylight Saving Time. In general this collection of
consists 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 takes
effect a rule that describes the day and time when the observance
takes effect
an optional name for the observance an optional name for the observance
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 described the observances over a period of time. Each observance is
using either a "STANDARD" or "DAYLIGHT" sub-component. The described using either a "STANDARD" or "DAYLIGHT" sub-component.
collection of these sub-components is used to describe the time zone The collection of these sub-components is used to describe the
for a given period of time. The offset to apply at any given time is time zone for a given period of time. The offset to apply at any
found by locating the observance that has the last onset date and given time is found by locating the observance that has the last
time before the time in question, and using the offset value from onset date and time before the time in question, and using the
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:
The mandatory "TZID" property is a text value that uniquely The mandatory "TZID" property is a text value that uniquely
identifies the VTIMZONE calendar component within the scope of an identifies the VTIMEZONE; and each MAY occur more than once.
iCalendar object. calendar component within the scope of an iCalendar object.
The optional "LAST-MODIFIED" property is a UTC value that specifies The optional "LAST-MODIFIED" property is a UTC value that
the date and time that this time zone definition was last updated. specifies the date and time that this time zone definition was
last updated.
The optional "TZURL" property is url value that points to a published The optional "TZURL" property is a url value that points to a
VTIMEZONE definition. TZURL SHOULD refer to a resource that is published VTIMEZONE definition. TZURL SHOULD refer to a resource
accessible by anyone who might need to interpret the object. This that is accessible by anyone who might need to interpret the
SHOULD NOT normally be a file: URL or other URL that is not widely- object. This SHOULD NOT normally be a "file" URL or other URL
accessible. that is not widely-accessible.
The collection of properties that are used to define the STANDARD and The collection of properties that are used to define the STANDARD
DAYLIGHT sub-components include: and DAYLIGHT sub-components include:
The mandatory "DTSTART" property gives the effective onset date and The mandatory "DTSTART" property gives the effective onset date
local time for the time zone sub-component definition. "DTSTART" in and local time for the time zone sub-component definition.
this usage MUST be specified as a local DATE-TIME value. "DTSTART" in this usage MUST be specified as a local DATE-TIME
value.
The mandatory "TZOFFSETFROM" property gives the UTC offset which is The mandatory "TZOFFSETFROM" property gives the UTC offset which
in use when the onset of this time zone observance begins. is 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, the onset for the time zone sub-component definition. For example,
following represents the time at which the observance of Standard the following represents the time at which the observance of
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
Figure 24
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) when time zone sub-component (Standard Time or Daylight Saving Time)
this observance is in use. when this observance is in use.
The optional "TZNAME" property is the customary name for the time The optional "TZNAME" property is the customary name for the time
zone. It may be specified multiple times, to allow for specifying zone. It may be specified multiple times, to allow for specifying
multiple language variants of the time zone names. This could be multiple language variants of the time zone names. This could be
used for displaying dates. used for displaying dates.
If specified, the onset for the observance defined by the time zone If specified, the onset for the observance defined by the time
sub-component is defined by either the "RRULE" or "RDATE" property. zone sub-component is defined by either the "RRULE" or "RDATE"
If neither is specified, only one sub-component can be specified in property. If neither is specified, only one sub-component can be
the "VTIMEZONE" calendar component and it is assumed that the single specified in the "VTIMEZONE" calendar component and it is assumed
observance specified is always in effect. that the single observance specified is always in effect.
The "RRULE" property defines the recurrence rule for the onset of the The "RRULE" property defines the recurrence rule for the onset of
observance defined by this time zone sub-component. Some specific the observance defined by this time zone sub-component. Some
requirements for the usage of RRULE for this purpose include: specific requirements for the usage of RRULE for this purpose
include:
If observance is known to have an effective end date, the "UNTIL" If observance is known to have an effective end date, the
recurrence rule parameter MUST be used to specify the last valid "UNTIL" recurrence rule parameter MUST be used to specify the
onset of this observance (i.e., the UNTIL date-time will be equal last valid onset of this observance (i.e., the UNTIL date-time
to the last instance generated by the recurrence pattern). It will be equal to the last instance generated by the recurrence
MUST be specified in UTC time. pattern). It MUST be specified in UTC time.
The "DTSTART" and the "TZOFFSETTO" properties MUST be used when The "DTSTART" and the "TZOFFSETTO" properties MUST be used when
generating the onset date-time values (instances) from the RRULE. generating the onset date-time values (instances) from the
RRULE.
Alternatively, the "RDATE" property can be used to define the onset Alternatively, the "RDATE" property can be used to define the
of the observance by giving the individual onset date and times. onset of the observance by giving the individual onset date and
"RDATE" in this usage MUST be specified as a local DATE-TIME value in times. "RDATE" in this usage MUST be specified as a local DATE-
UTC time. TIME value in UTC time.
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:
Example 1: Time zone information for the Eastern United States using This is an example showing time zone information for the Eastern
"RDATE" property. Note that this is only suitable for a recurring United States using "RDATE" property. Note that this is only
event that starts on or later than April 6, 1997 at 03:00:00 EDT suitable for a recurring event that starts on or later than April
(i.e., the earliest effective transition date and time) and ends no 6, 1997 at 03:00:00 EDT (i.e., the earliest effective transition
later than April 7, 1998 02:00:00 EST (i.e., latest valid date and date and time) and ends no later than April 7, 1998 02:00:00 EST
time for EST in this scenario). For example, this can be used for a (i.e., latest valid date and time for EST in this scenario). For
recurring event that occurs every Friday, 8am-9:00 AM, starting June example, this can be used for a recurring event that occurs every
1, 1997, ending December 31, 1997. Friday, 8:00AM-9:00 AM, starting June 1, 1997, ending December 31,
1997.
BEGIN:VTIMEZONE BEGIN:VTIMEZONE
TZID:US-Eastern TZID:US-Eastern
LAST-MODIFIED:19870101T000000Z LAST-MODIFIED:19870101T000000Z
BEGIN:STANDARD BEGIN:STANDARD
DTSTART:19971026T020000 DTSTART:19971026T020000
RDATE:19971026T020000 RDATE:19971026T020000
TZOFFSETFROM:-0400 TZOFFSETFROM:-0400
TZOFFSETTO:-0500 TZOFFSETTO:-0500
TZNAME:EST TZNAME:EST
END:STANDARD END:STANDARD
BEGIN:DAYLIGHT BEGIN:DAYLIGHT
DTSTART:19970406T020000 DTSTART:19970406T020000
RDATE:19970406T020000 RDATE:19970406T020000
TZOFFSETFROM:-0500 TZOFFSETFROM:-0500
TZOFFSETTO:-0400 TZOFFSETTO:-0400
TZNAME:EDT TZNAME:EDT
END:DAYLIGHT END:DAYLIGHT
END:VTIMEZONE END:VTIMEZONE
Figure 25 This is a simple example showing the current time zone rules for
Example 2: Current time zone rules for the Eastern United States the Eastern United States using a RRULE recurrence pattern. Note
using a RRULE recurrence pattern. Note that there is no effective that there is no effective end date to either of the Standard Time
end date to either of the Standard Time or Daylight Time rules. This or Daylight Time rules. This information would be valid for a
information would be valid for a recurring event starting today and recurring event starting today and continuing indefinitely.
continuing indefinitely.
BEGIN:VTIMEZONE BEGIN:VTIMEZONE
TZID:US-Eastern TZID:US-Eastern
LAST-MODIFIED:19870101T000000Z LAST-MODIFIED:19870101T000000Z
TZURL:http://zones.stds_r_us.net/tz/US-Eastern TZURL:http://zones.example.com/tz/US-Eastern.ics
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 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
Figure 26 This is an example showing a fictitious set of rules for the
Example 3: A fictitious set of rules for the Eastern United States, Eastern United States, where the Daylight Time rule has an
where the Daylight Time rule has an effective end date (i.e., after effective end date (i.e., after that date, Daylight Time is no
that date, Daylight Time is no longer observed). longer observed).
BEGIN:VTIMEZONE BEGIN:VTIMEZONE
TZID:US- -Fictitious-Eastern TZID:US- -Fictitious-Eastern
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
This is an example showing a fictitious set of rules for the
Figure 27 Eastern United States, where the first Daylight Time rule has an
Example 4: A fictitious set of rules for the Eastern United States, effective end date. There is a second Daylight Time rule that
where the first Daylight Time rule has an effective end date. There picks up where the other left off.
is a second Daylight Time rule that picks up where the other left
off.
BEGIN:VTIMEZONE BEGIN:VTIMEZONE
TZID:US- -Fictitious-Eastern TZID:US- -Fictitious-Eastern
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
skipping to change at page 38, line 35 skipping to change at page 66, line 35
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
Figure 28 3.6.6. Alarm Component
7.6. 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.
Formal 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 / procprop) (audioprop / dispprop / emailprop / procprop)
"END" ":" "VALARM" CRLF "END" ":" "VALARM" CRLF
audioprop = 2*( audioprop = 2*(
; 'action' and 'trigger' are both REQUIRED, ; 'action' and 'trigger' are both REQUIRED,
; but MUST NOT occur more than once ; but MUST NOT occur more than once
action / trigger / action / trigger /
; 'duration' and 'repeat' are both optional, ; 'duration' and 'repeat' are both optional,
; and MUST NOT occur more than once each, ; and MUST NOT occur more than once each,
; but if one occurs, so MUST the other ; but if one occurs, so MUST the other
duration / repeat / duration / repeat /
skipping to change at page 39, line 41 skipping to change at page 67, line 40
action / description / trigger / action / description / trigger /
; 'duration' and 'repeat' are both optional, ; 'duration' and 'repeat' are both optional,
; and MUST NOT occur more than once each, ; and MUST NOT occur more than once each,
; but if one occurs, so MUST the other ; but if one occurs, so MUST the other
duration / repeat / duration / repeat /
; the following is optional, ; the following is optional,
; and MAY occur more than once ; and MAY occur more than once
*x-prop x-prop
) )
emailprop = 5*( emailprop = 5*(
; the following are all REQUIRED, ; the following are all REQUIRED,
; but MUST NOT occur more than once ; but MUST NOT occur more than once
action / description / trigger / summary action / description / trigger / summary /
; the following is REQUIRED, ; the following is REQUIRED,
; and MAY occur more than once ; and MAY occur more than once
attendee / attendee /
; 'duration' and 'repeat' are both optional, ; 'duration' and 'repeat' are both optional,
; and MUST NOT occur more than once each, ; and MUST NOT occur more than once each,
; but if one occurs, so MUST the other ; but if one occurs, so MUST the other
duration / repeat / duration / repeat /
skipping to change at page 41, line 4 skipping to change at page 68, line 42
duration / repeat / duration / repeat /
; 'description' is optional, ; 'description' is optional,
; and MUST NOT occur more than once ; and MUST NOT occur more than once
description / description /
; the following is optional, ; the following is optional,
; and MAY occur more than once ; and MAY occur more than once
x-prop x-prop
) )
Figure 29
Description: A "VALARM" calendar component is a grouping of component Description: A "VALARM" calendar component is a grouping of component
properties that is a reminder or alarm for an event or a to-do. For properties that is a reminder or alarm for an event or a to-do.
example, it may be used to define a reminder for a pending event or For example, it may be used to define a reminder for a pending
an overdue to-do. 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 the "TRIGGER" properties. The "ACTION" property further constrains
"VALARM" calendar component in the following ways: the "VALARM" calendar component in the following ways:
When the action is "AUDIO", the alarm can also include one and only When the action is "AUDIO", the alarm can also include one and
one "ATTACH" property, which MUST point to a sound resource, which is only one "ATTACH" property, which MUST point to a sound resource,
rendered when the alarm is triggered. which is rendered when the alarm is triggered.
When the action is "DISPLAY", the alarm MUST also include a When the action is "DISPLAY", the alarm MUST also include a
"DESCRIPTION" property, which contains the text to be displayed when "DESCRIPTION" property, which contains the text to be displayed
the alarm is triggered. when the alarm is triggered.
When the action is "EMAIL", the alarm MUST include a "DESCRIPTION" When the action is "EMAIL", the alarm MUST include a "DESCRIPTION"
property, which contains the text to be used as the message body, a property, which contains the text to be used as the message body,
"SUMMARY" property, which contains the text to be used as the message a "SUMMARY" property, which contains the text to be used as the
subject, and one or more "ATTENDEE" properties, which contain the message subject, and one or more "ATTENDEE" properties, which
email address of attendees to receive the message. It can also contain the email address of attendees to receive the message. It
include one or more "ATTACH" properties, which are intended to be can also include one or more "ATTACH" properties, which are
sent as message attachments. When the alarm is triggered, the email intended to be sent as message attachments. When the alarm is
message is sent. triggered, the email message is sent.
When the action is "PROCEDURE", the alarm MUST include one and only When the action is "PROCEDURE", the alarm MUST include one and
one "ATTACH" property, which MUST point to a procedure resource, only one "ATTACH" property, which MUST point to a procedure
which is invoked when the alarm is triggered. resource, which is invoked when the alarm is triggered.
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 components "VEVENT" or "VTODO" calendar component. "VALARM" calendar
cannot be nested. Multiple mutually independent "VALARM" calendar components cannot be nested. Multiple mutually independent
components can be specified for a single "VEVENT" or "VTODO" calendar "VALARM" calendar components can be specified for a single
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 an The "TRIGGER" property specifies a duration prior to the start of
event or a to-do. The "TRIGGER" edge may be explicitly set to be an event or a to-do. The "TRIGGER" edge may be explicitly set to
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 calendar property value type can alternatively be set to an absolute
date and time of day value. calendar date and time of day value.
In an alarm set to trigger on the "START" of an event or to-do, the In an alarm set to trigger on the "START" of an event or to-do,
"DTSTART" property MUST be present in the associated event or to-do. the "DTSTART" property MUST be present in the associated event or
In an alarm in a "VEVENT" calendar component set to trigger on the to-do. In an alarm in a "VEVENT" calendar component set to
"END" of the event, either the "DTEND" property MUST be present, or trigger on the "END" of the event, either the "DTEND" property
the "DTSTART" and "DURATION" properties MUST both be present. In an MUST be present, or the "DTSTART" and "DURATION" properties MUST
alarm in a "VTODO" calendar component set to trigger on the "END" of both be present. In an alarm in a "VTODO" calendar component set
the to-do, either the "DUE" property MUST be present, or the to trigger on the "END" of the to-do, either the "DUE" property
"DTSTART" and "DURATION" properties MUST both be present. MUST be present, or the "DTSTART" and "DURATION" properties MUST
both be present.
The alarm can be defined such that it triggers repeatedly. A The alarm can be defined such that it triggers repeatedly. A
definition of an alarm with a repeating trigger MUST include both the definition of an alarm with a repeating trigger MUST include both
"DURATION" and "REPEAT" properties. The "DURATION" property the "DURATION" and "REPEAT" properties. The "DURATION" property
specifies the delay period, after which the alarm will repeat. The specifies the delay period, after which the alarm will repeat.
"REPEAT" property specifies the number of additional repetitions that The "REPEAT" property specifies the number of additional
the alarm will triggered. This repitition count is in addition to repetitions that the alarm will be triggered. This repetition
the initial triggering of the alarm. Both of these properties MUST count is in addition to the initial triggering of the alarm. Both
be present in order to specify a repeating alarm. If one of these of these properties MUST be present in order to specify a
two properties is absent, then the alarm will not repeat beyond the repeating alarm. If one of these two properties is absent, then
initial trigger. the alarm will not repeat beyond the initial trigger.
The "ACTION" property is used within the "VALARM" calendar component The "ACTION" property is used within the "VALARM" calendar
to specify the type of action invoked when the alarm is triggered. component to specify the type of action invoked when the alarm is
The "VALARM" properties provide enough information for a specific triggered. The "VALARM" properties provide enough information for
action to be invoked. It is typically the responsibility of a a specific action to be invoked. It is typically the
"Calendar User Agent" (CUA) to deliver the alarm in the specified responsibility of a "Calendar User Agent" (CUA) to deliver the
fashion. An "ACTION" property value of AUDIO specifies an alarm that alarm in the specified fashion. An "ACTION" property value of
causes a sound to be played to alert the user; DISPLAY specifies an AUDIO specifies an alarm that causes a sound to be played to alert
alarm that causes a text message to be displayed to the user; EMAIL the user; DISPLAY specifies an alarm that causes a text message to
specifies an alarm that causes an electronic email message to be be displayed to the user; EMAIL specifies an alarm that causes an
delivered to one or more email addresses; and PROCEDURE specifies an electronic email message to be delivered to one or more email
alarm that causes a procedure to be executed. The "ACTION" property addresses; and PROCEDURE specifies an alarm that causes a
MUST specify one and only one of these values. procedure to be executed. The "ACTION" property MUST specify one
and only one of these values.
In an AUDIO alarm, if the optional "ATTACH" property is included, it In an AUDIO alarm, if the optional "ATTACH" property is included,
MUST specify an audio sound resource. The intention is that the it MUST specify an audio sound resource. The intention is that
sound will be played as the alarm effect. If an "ATTACH" property is the sound will be played as the alarm effect. If an "ATTACH"
specified that does not refer to a sound resource, or if the property is specified that does not refer to a sound resource, or
specified sound resource cannot be rendered (because its format is if the specified sound resource cannot be rendered (because its
unsupported, or because it cannot be retrieved), then the CUA or format is unsupported, or because it cannot be retrieved), then
other entity responsible for playing the sound may choose a fallback the CUA or other entity responsible for playing the sound may
action, such as playing a built-in default sound, or playing no sound choose a fallback action, such as playing a built-in default
at all. sound, or playing no sound at all.
In a DISPLAY alarm, the intended alarm effect is for the text value In a DISPLAY alarm, the intended alarm effect is for the text
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 message In an EMAIL alarm, the intended alarm effect is for an email
to be composed and delivered to all the addresses specified by the message to be composed and delivered to all the addresses
"ATTENDEE" properties in the "VALARM" calendar component. The specified by the "ATTENDEE" properties in the "VALARM" calendar
"DESCRIPTION" property of the "VALARM" calendar component MUST be component. The "DESCRIPTION" property of the "VALARM" calendar
used as the body text of the message, and the "SUMMARY" property MUST component MUST be used as the body text of the message, and the
be used as the subject text. Any "ATTACH" properties in the "VALARM" "SUMMARY" property MUST be used as the subject text. Any "ATTACH"
calendar component SHOULD be sent as attachments to the message. properties in the "VALARM" calendar component SHOULD be sent as
attachments to the message.
In a PROCEDURE alarm, the "ATTACH" property in the "VALARM" calendar In a PROCEDURE alarm, the "ATTACH" property in the "VALARM"
component MUST specify a procedure or program that is intended to be calendar component MUST specify a procedure or program that is
invoked as the alarm effect. If the procedure or program is in a intended to be invoked as the alarm effect. If the procedure or
format that cannot be rendered, then no procedure alarm will be program is in a format that cannot be rendered, then no procedure
invoked. If the "DESCRIPTION" property is present, its value alarm will be invoked. If the "DESCRIPTION" property is present,
specifies the argument string to be passed to the procedure or its value specifies the argument string to be passed to the
program. "Calendar User Agents" that receive an iCalendar object procedure or program. "Calendar User Agents" that receive an
with this category of alarm, can disable or allow the "Calendar User" iCalendar object with this category of alarm, can disable or allow
to disable, or otherwise ignore this type of alarm. While a very the "Calendar User" to disable, or otherwise ignore this type of
useful alarm capability, the PROCEDURE type of alarm SHOULD be alarm. While a very useful alarm capability, the PROCEDURE type
treated by the "Calendar User Agent" as a potential security risk. of alarm SHOULD be treated by the "Calendar User Agent" as a
potential security risk.
Example 1: A "VALARM" calendar component that specifies an audio Example: The following example is for a "VALARM" calendar component
alarm that will sound at a precise time and repeat 4 more times at 15 that specifies an audio alarm that will sound at a precise time
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://host.com/pub/sounds/bell-01.aud ATTACH;FMTTYPE=audio/basic:ftp://host.com/pub/sounds/bell-01.aud
END:VALARM END:VALARM
Figure 30 The following example is for a "VALARM" calendar component that
specifies a display alarm that will trigger 30 minutes before the
Example 2: A "VALARM" calendar component that specifies a display scheduled start of the event or the due date/time of the to-do it
alarm that will trigger 30 minutes before the scheduled start of the is associated with and will repeat 2 more times at 15 minute
event or the due date/time of the to-do it is associated with and intervals:
will repeat 2 more times at 15 minute intervals:
BEGIN:VALARM BEGIN:VALARM
TRIGGER:-PT30M TRIGGER:-PT30M
REPEAT:2 REPEAT:2
DURATION:PT15M DURATION:PT15M
ACTION:DISPLAY ACTION:DISPLAY
DESCRIPTION:Breakfast meeting with executive\n DESCRIPTION:Breakfast meeting with executive\n
team at 8:30 AM EST. team at 8:30 AM EST.
END:VALARM END:VALARM
Figure 31
Example 3: A "VALARM" calendar component that specifies an email The following example is for a "VALARM" calendar component that
alarm that will trigger 2 days before the scheduled due date/time of specifies an email alarm that will trigger 2 days before the
a to-do it is associated with. It does not repeat. The email has a scheduled due date/time of a to-do it is associated with. It does
subject, body and attachment link. not repeat. The email has a subject, body and attachment link.
BEGIN:VALARM BEGIN:VALARM
TRIGGER:-P2D TRIGGER:-P2D
ACTION:EMAIL ACTION:EMAIL
ATTENDEE:MAILTO:john_doe@host.com ATTENDEE:MAILTO:john_doe@host.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://host.com/templates/agen ATTACH;FMTTYPE=application/msword:http://host.com/templates/agen
da.doc da.doc
END:VALARM END:VALARM
Figure 32 The following example is for a "VALARM" calendar component that
specifies a procedural alarm that will trigger at a precise date/
Example 4: A "VALARM" calendar component that specifies a procedural time and will repeat 23 more times at one hour intervals. The
alarm that will trigger at a precise date/time and will repeat 23 alarm will invoke a procedure file.
more times at one hour intervals. The alarm will invoke a procedure
file.
BEGIN:VALARM BEGIN:VALARM
TRIGGER;VALUE=DATE-TIME:19980101T050000Z TRIGGER;VALUE=DATE-TIME:19980101T050000Z
REPEAT:23 REPEAT:23
DURATION:PT1H DURATION:PT1H
ACTION:PROCEDURE ACTION:PROCEDURE
ATTACH;FMTTYPE=application/octet-stream:ftp://host.com/novo- ATTACH;FMTTYPE=application/octet-stream:ftp://host.com/novo-
procs/felizano.exe procs/felizano.exe
END:VALARM END:VALARM
Figure 33 3.7. Calendar Properties
8. Properties
A property is the definition of an individual attribute describing a
calendar or a calendar component. A property takes the form defined
by the "contentline" notation defined in section 4.1.1.
The following is an example of a property:
DTSTART:19960415T133000Z
This memo imposes no ordering of properties within an iCalendar
object.
Property names, parameter names and enumerated parameter values are
case insensitive. For example, the property name "DUE" is the same
as "due" and "Due", DTSTART;TZID=US-Eastern:19980714T120000 is the
same as DtStart;TzID=US-Eastern:19980714T120000.
8.1. 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"
property and prior to any calendar component. delimiter string and prior to any calendar component.
8.1.1. Calendar Scale 3.7.1. Calendar Scale
Property Name: CALSCALE Property Name: CALSCALE
Purpose: This property defines the calendar scale used for the Purpose: This property defines the calendar scale used for the
calendar information specified in the iCalendar object. calendar information specified in the iCalendar object.
Value Type: TEXT Value Type: TEXT
do Property Parameters: Non-standard property parameters can be Property Parameters: Non-standard property parameters can be
specified on this property. specified on this property.
Conformance: Property can be specified in an iCalendar object. The Conformance: Property can be specified in an iCalendar object. The
default value is "GREGORIAN". default value is "GREGORIAN".
Description: This memo is based on the Gregorian calendar scale. The Description: This memo is based on the Gregorian calendar scale. The
Gregorian calendar scale is assumed if this property is not specified Gregorian calendar scale is assumed if this property is not
in the iCalendar object. It is expected that other calendar scales specified in the iCalendar object. It is expected that other
will be defined in other specifications or by future versions of this calendar scales will be defined in other specifications or by
memo. future versions of this memo.
Formal Definition: The property is defined by the following notation: Format Definition: The property is defined by the following notation:
calscale = "CALSCALE" calparam ":" calvalue CRLF calscale = "CALSCALE" calparam ":" calvalue CRLF
calparam = *(";" xparam) calparam = *(";" xparam)
calvalue = "GREGORIAN" / iana-token calvalue = "GREGORIAN" / iana-token
Figure 35
Example: The following is an example of this property: Example: The following is an example of this property:
CALSCALE:GREGORIAN CALSCALE:GREGORIAN
Figure 36 3.7.2. Method
8.1.2. Method
Property Name: METHOD Property Name: METHOD
Purpose: This property defines the iCalendar object method associated Purpose: This property defines the iCalendar object method associated
with the calendar object. with the calendar object.
Value Type: TEXT Value Type: TEXT
Property Parameters: Non-standard property parameters can be Property Parameters: Non-standard property parameters can be
specified on this property. specified on this property.
Conformance: The property can be specified in an iCalendar object. Conformance: The property can be specified in an iCalendar 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. This property can only appear once within the iCalendar value. This property can only appear once within the iCalendar
object. If either the "METHOD" property or the Content-Type "method" object. If either the "METHOD" property or the Content-Type
parameter is specified, then the other MUST also be specified. "method" parameter is specified, then the other MUST also be
specified.
No methods are defined by this specification. This is the subject of No methods are defined by this specification. This is the subject
other specifications, such as the iCalendar Transport-independent of other specifications, such as the iCalendar Transport-
Interoperability Protocol (iTIP) defined by [ITIP]. independent Interoperability Protocol (iTIP) defined by [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 some iCalendar object is merely being used to transport a snapshot of
calendar information; without the intention of conveying a scheduling some calendar information; without the intention of conveying a
semantic. scheduling semantic.
Formal Definition: The property is defined by the following notation: Format Definition: The property is defined by the following notation:
method = "METHOD" metparam ":" metvalue CRLF method = "METHOD" metparam ":" metvalue CRLF
metparam = *(";" xparam) metparam = *(";" xparam)
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 request for a meeting: convey that the iCalendar object is a request for a meeting:
METHOD:REQUEST METHOD:REQUEST
Figure 38 3.7.3. Product Identifier
8.1.3. 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
Property Parameters: Non-standard property parameters can be Property Parameters: Non-standard property parameters can be
specified on this property. specified on this property.
Conformance: The property MUST be specified once in an iCalendar Conformance: The property MUST be specified once in an iCalendar
object. object.
Description: The vendor of the implementation SHOULD assure that this Description: The vendor of the implementation SHOULD assure that this
is a globally unique identifier; using some technique such as an FPI is a globally unique identifier; using some technique such as an
value, as defined in [ISO 9070]. 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.
Formal Definition: The property is defined by the following notation: Format Definition: The property is defined by the following notation:
prodid = "PRODID" pidparam ":" pidvalue CRLF prodid = "PRODID" pidparam ":" pidvalue CRLF
pidparam = *(";" xparam) pidparam = *(";" xparam)
pidvalue = text pidvalue = text
;Any text that describes the product and version ;Any text that describes the product and version
;and that is generally assured of being unique. ;and that is generally assured of being unique.
Figure 39
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
Figure 40 3.7.4. Version
8.1.4. 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.
Value Type: TEXT Value Type: TEXT
Property Parameters: Non-standard property parameters can be Property Parameters: Non-standard property parameters can be
specified on this property. specified on this property.
Conformance: This property MUST be specified by an iCalendar object, Conformance: This property MUST be specified by an iCalendar object,
but MUST only be specified once. but MUST only be specified once.
Description: A value of "2.0" corresponds to this memo. Description: A value of "2.0" corresponds to this memo.
Formal Definition: The property is defined by the following notation: Format Definition: The property is defined by the following notation:
version = "VERSION" verparam ":" vervalue CRLF version = "VERSION" verparam ":" vervalue CRLF
verparam = *(";" xparam) verparam = *(";" xparam)
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
Example: The following is an example of this property: Example: The following is an example of this property:
VERSION:2.0 VERSION:2.0
8.2. Descriptive 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. These specify specified by each component property definition.
descriptive information about calendar components.
8.2.1. Attachment 3.8.1. Descriptive Component Properties
The following properties specify descriptive information about
calendar components.
3.8.1.1. Attachment
Property Name: ATTACH Property Name: ATTACH
Purpose: The property provides the capability to associate a document Purpose: The property provides the capability to associate a document
object with a calendar component. 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.
skipping to change at page 50, line 33 skipping to change at page 77, line 31
) )
Example: The following are examples of this property: Example: The following are examples of this property:
ATTACH:CID:jsmith.part3.960817T083000.xyzMail@host1.com ATTACH:CID:jsmith.part3.960817T083000.xyzMail@host1.com
ATTACH;FMTTYPE=application/postscript:ftp://xyzCorp.com/pub/ ATTACH;FMTTYPE=application/postscript:ftp://xyzCorp.com/pub/
reports/r-960812.ps reports/r-960812.ps
8.2.2. 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: Non-standard and language property parameters Property Parameters: Non-standard and language property parameters
can be specified on this property. 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.
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. Within for a calendar component of a particular type and category.
the "VEVENT", "VTODO" or "VJOURNAL" calendar components, more than Within the "VEVENT", "VTODO" or "VJOURNAL" calendar components,
one category can be specified as a list of categories separated by more than one category can be specified as a list of categories
the COMMA character (US-ASCII decimal 44). separated by the COMMA character (US-ASCII decimal 44).
Format Definition: The property is defined by the following 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
(";" xparam) (";" xparam)
) )
The following are examples of categories. Example: The following are examples of this property:
CATEGORIES:APPOINTMENT,EDUCATION CATEGORIES:APPOINTMENT,EDUCATION
CATEGORIES:MEETING CATEGORIES:MEETING
8.2.3. 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: Non-standard property parameters can be Property Parameters: Non-standard property parameters can be
specified on this property. 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.
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 provides a general security system within a calendar application. It
method of capturing the scope of the access the calendar owner provides a method of capturing the scope of the access the
intends for information within an individual calendar entry. The calendar owner intends for information within an individual
access classification of an individual iCalendar component is useful calendar entry. The access classification of an individual
when measured along with the other security components of a calendar iCalendar component is useful when measured along with the other
system (e.g., calendar user authentication, authorization, access security components of a calendar system (e.g., calendar user
rights, access role, etc.). Hence, the semantics of the individual authentication, authorization, access rights, access role, etc.).
access classifications cannot be completely defined by this memo
alone. Additionally, due to the "blind" nature of most exchange
processes using this memo, these access classifications cannot serve
as an enforcement statement for a system receiving an iCalendar
object. Rather, they provide a method for capturing the intention of
the calendar owner for the access to the calendar component.
Formal Definition: The property is defined by the following notation: Hence, the semantics of the individual access classifications
cannot be completely defined by this memo alone. Additionally,
due to the "blind" nature of most exchange processes using this
memo, these access classifications cannot serve as an enforcement
statement for a system receiving an iCalendar object. Rather,
they provide a method for capturing the intention of the calendar
owner for the access to the calendar component.
Format Definition: The property is defined by the following notation:
class = "CLASS" classparam ":" classvalue CRLF class = "CLASS" classparam ":" classvalue CRLF
classparam = *(";" xparam) classparam = *(";" xparam)
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
8.2.4. 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: Non-standard, alternate text representation and Property Parameters: Non-standard, alternate text representation and
language property parameters can be specified on this property. language property parameters can be specified on this property.
Conformance: This property can be specified in "VEVENT", "VTODO", Conformance: This property can be specified in "VEVENT", "VTODO",
"VJOURNAL", "VTIMEZONE" or "VFREEBUSY" calendar components. "VJOURNAL", "VTIMEZONE" or "VFREEBUSY" calendar components.
Description: The property can be specified multiple times. Description: The property can be specified multiple times.
Formal Definition: The property is defined by the following notation: Format Definition: The property is defined by the following 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) /
skipping to change at page 53, line 30 skipping to change at page 80, line 28
) )
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
8.2.5. 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: Non-standard, alternate text representation and Property Parameters: Non-standard, alternate text representation and
language property parameters can be specified on this property. language property parameters can be specified on this property.
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 component. specified multiple times only within a "VJOURNAL" calendar
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 decriptions associated with the activity.
This property is used in the "VJOURNAL" calendar component to capture This property is used in the "VJOURNAL" calendar component to
one more textual journal entries. capture one more textual journal entries.
This property is used in the "VALARM" calendar component to capture This property is used in the "VALARM" calendar component to
the display text for a DISPLAY category of alarm, to capture the body capture the display text for a DISPLAY category of alarm, to
text for an EMAIL category of alarm and to capture the argument capture the body text for an EMAIL category of alarm and to
string for a PROCEDURE category of alarm. capture the argument string for a PROCEDURE category of alarm.
Formal Definition: The property is defined by the following notation: Format Definition: The property is defined by the following 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) /
skipping to change at page 54, line 39 skipping to change at page 81, line 41
DESCRIPTION:Meeting to provide technical review for "Phoenix" DESCRIPTION:Meeting to provide technical review for "Phoenix"
design.\n Happy Face Conference Room. Phoenix design team design.\n Happy Face Conference Room. Phoenix design team
MUST attend this meeting.\n RSVP to team leader. MUST attend this meeting.\n RSVP to team leader.
The following is an example of the property with folding of long The following is an example of the property with folding of long
lines: lines:
DESCRIPTION:Last draft of the new novel is to be completed DESCRIPTION:Last draft of the new novel is to be completed
for the editor's proof today. for the editor's proof today.
8.2.6. 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 Value Type: FLOAT. The value MUST be two SEMICOLON separated FLOAT
values. values.
Property Parameters: Non-standard property parameters can be Property Parameters: Non-standard property parameters can be
specified on this property. specified on this property.
Conformance: This property can be specified in "VEVENT" or "VTODO" Conformance: This property can be specified in "VEVENT" or "VTODO"
calendar components. calendar components.
Description: The property value specifies latitude and longitude, in Description: The property value specifies latitude and longitude, in
that order (i.e., "LAT LON" ordering). The longitude represents the that order (i.e., "LAT LON" ordering). The longitude represents
location east or west of the prime meridian as a positive or negative the location east or west of the prime meridian as a positive or
real number, respectively. The longitude and latitude values MAY be negative real number, respectively. The longitude and latitude
specified up to six decimal places, which will allow for accuracy to values MAY be specified up to six decimal places, which will allow
within one meter of geographical position. Receiving applications for accuracy to within one meter of geographical position.
MUST accept values of this precision and MAY truncate values of Receiving applications MUST accept values of this precision and
greater precision. MAY truncate values of greater precision.
Values for latitude and longitude shall be expressed as decimal Values for latitude and longitude shall be expressed as decimal
fractions of degrees. Whole degrees of latitude shall be represented fractions of degrees. Whole degrees of latitude shall be
by a two-digit decimal number ranging from 0 through 90. Whole represented by a two-digit decimal number ranging from 0 through
degrees of longitude shall be represented by a decimal number ranging 90. Whole degrees of longitude shall be represented by a decimal
from 0 through 180. When a decimal fraction of a degree is number ranging from 0 through 180. When a decimal fraction of a
specified, it shall be separated from the whole number of degrees by degree is specified, it shall be separated from the whole number
a decimal point. of degrees by a decimal point.
Latitudes north of the equator shall be specified by a plus sign (+), Latitudes north of the equator shall be specified by a plus sign
or by the absence of a minus sign (-), preceding the digits (+), or by the absence of a minus sign (-), preceding the digits
designating degrees. Latitudes south of the Equator shall be designating degrees. Latitudes south of the Equator shall be
designated by a minus sign (-) preceding the digits designating designated by a minus sign (-) preceding the digits designating
degrees. A point on the Equator shall be assigned to the Northern degrees. A point on the Equator shall be assigned to the Northern
Hemisphere. Hemisphere.
Longitudes east of the prime meridian shall be specified by a plus Longitudes east of the prime meridian shall be specified by a plus
sign (+), or by the absence of a minus sign (-), preceding the digits sign (+), or by the absence of a minus sign (-), preceding the
designating degrees. Longitudes west of the meridian shall be digits designating degrees. Longitudes west of the meridian shall
designated by minus sign (-) preceding the digits designating be designated by minus sign (-) preceding the digits designating
degrees. A point on the prime meridian shall be assigned to the degrees. A point on the prime meridian shall be assigned to the
Eastern Hemisphere. A point on the 180th meridian shall be assigned Eastern Hemisphere. A point on the 180th meridian shall be
to the Western Hemisphere. One exception to this last convention is assigned to the Western Hemisphere. One exception to this last
permitted. For the special condition of describing a band of convention is permitted. For the special condition of describing
latitude around the earth, the East Bounding Coordinate data element a band of latitude around the earth, the East Bounding Coordinate
shall be assigned the value +180 (180) degrees. data element shall be assigned the value +180 (180) degrees.
Any spatial address with a latitude of +90 (90) or -90 degrees will Any spatial address with a latitude of +90 (90) or -90 degrees
specify the position at the North or South Pole, respectively. The will specify the position at the North or South Pole,
component for longitude may have any legal value. respectively. The component for longitude may have any legal
value.
With the exception of the special condition described above, this With the exception of the special condition described above, this
form is specified in Department of Commerce, 1986, Representation of form is specified in Department of Commerce, 1986, Representation
geographic point locations for information interchange (Federal of geographic point locations for information interchange (Federal
Information Processing Standard 70-1): Washington, Department of Information Processing Standard 70-1): Washington, Department of
Commerce, National Institute of Standards and Technology. Commerce, National Institute of Standards and Technology.
The simple formula for converting degrees-minutes-seconds into The simple formula for converting degrees-minutes-seconds into
decimal degrees is: decimal degrees is:
decimal = degrees + minutes/60 + seconds/3600. decimal = degrees + minutes/60 + seconds/3600.
Formal Definition: The property is defined by the following notation: Format Definition: The property is defined by the following notation:
geo = "GEO" geoparam ":" geovalue CRLF geo = "GEO" geoparam ":" geovalue CRLF
geoparam = *(";" xparam) geoparam = *(";" xparam)
geovalue = float ";" float geovalue = float ";" float
;Latitude and Longitude components ;Latitude and Longitude components
Example: The following is an example of this property: Example: The following is an example of this property:
GEO:37.386013;-122.082932 GEO:37.386013;-122.082932
8.2.7. Location 3.8.1.7. Location
Property Name: LOCATION Property Name: LOCATION
Purpose: The property defines the intended venue for the activity Purpose: The property defines the intended venue for the activity
defined by a calendar component. defined by a calendar component.
Value Type: TEXT Value Type: TEXT
Property Parameters: Non-standard, alternate text representation and Property Parameters: Non-standard, alternate text representation and
language property parameters can be specified on this property. language property parameters can be specified on this property.
skipping to change at page 57, line 30 skipping to change at page 84, line 30
) )
Example: The following are some examples of this property: Example: The following are some examples of this property:
LOCATION:Conference Room - F123, Bldg. 002 LOCATION:Conference Room - F123, Bldg. 002
LOCATION;ALTREP="http://xyzcorp.com/conf-rooms/f123.vcf": LOCATION;ALTREP="http://xyzcorp.com/conf-rooms/f123.vcf":
Conference Room - F123, Bldg. 002 Conference Room - F123, Bldg. 002
8.2.8. Percent Complete 3.8.1.8. Percent Complete
Property Name: PERCENT-COMPLETE Property Name: PERCENT-COMPLETE
Purpose: This property is used by an assignee or delegatee of a to-do Purpose: This property is used by an assignee or delegatee of a to-do
to convey the percent completion of a to-do to the Organizer. to convey the percent completion of a to-do to the Organizer.
Value Type: INTEGER Value Type: INTEGER
Property Parameters: Non-standard property parameters can be Property Parameters: Non-standard property parameters can be
specified on this property. specified on this property.
Conformance: This property can be specified in a "VTODO" calendar Conformance: This property can be specified in a "VTODO" calendar
component. component.
Description: The property value is a positive integer between zero Description: The property value is a positive integer between zero
and one hundred. A value of "0" indicates the to-do has not yet been and one hundred. A value of "0" indicates the to-do has not yet
started. A value of "100" indicates that the to-do has been been started. A value of "100" indicates that the to-do has been
completed. Integer values in between indicate the percent partially completed. Integer values in between indicate the percent
complete. partially complete.
When a to-do is assigned to multiple individuals, the property value When a to-do is assigned to multiple individuals, the property
indicates the percent complete for that portion of the to-do assigned value indicates the percent complete for that portion of the to-do
to the assignee or delegatee. For example, if a to-do is assigned to assigned to the assignee or delegatee. For example, if a to-do is
both individuals "A" and "B". A reply from "A" with a percent assigned to both individuals "A" and "B". A reply from "A" with a
complete of "70" indicates that "A" has completed 70% of the to-do percent complete of "70" indicates that "A" has completed 70% of
assigned to them. A reply from "B" with a percent complete of "50" the to-do assigned to them. A reply from "B" with a percent
indicates "B" has completed 50% of the to-do assigned to them. complete of "50" indicates "B" has completed 50% of the to-do
assigned to them.
Format Definition: The property is defined by the following notation: Format Definition: The property is defined by the following notation:
percent = "PERCENT-COMPLETE" pctparam ":" integer CRLF percent = "PERCENT-COMPLETE" pctparam ":" integer CRLF
pctparam = *(";" xparam) pctparam = *(";" xparam)
Example: The following is an example of this property to show 39% Example: The following is an example of this property to show 39%
completion: completion:
PERCENT-COMPLETE:39 PERCENT-COMPLETE:39
8.2.9. Priority 3.8.1.9. Priority
Property Name: PRIORITY Property Name: PRIORITY
Purpose: The property defines the relative priority for a calendar Purpose: The property defines the relative priority for a calendar
component. component.
Value Type: INTEGER Value Type: INTEGER
Property Parameters: Non-standard property parameters can be Property Parameters: Non-standard property parameters can be
specified on this property. specified on this property.
Conformance: The property can be specified in a "VEVENT" or "VTODO" Conformance: The property can be specified in a "VEVENT" or "VTODO"
calendar component. calendar component.
Description: The priority is specified as an integer in the range Description: The priority is specified as an integer in the range
zero to nine. A value of zero (US-ASCII decimal 48) specifies an zero to nine. A value of zero (US-ASCII decimal 48) specifies an
undefined priority. A value of one (US-ASCII decimal 49) is the undefined priority. A value of one (US-ASCII decimal 49) is the
highest priority. A value of two (US-ASCII decimal 50) is the second highest priority. A value of two (US-ASCII decimal 50) is the
highest priority. Subsequent numbers specify a decreasing ordinal second highest priority. Subsequent numbers specify a decreasing
priority. A value of nine (US-ASCII decimal 58) is the lowest ordinal priority. A value of nine (US-ASCII decimal 58) is the
priority. lowest priority.
A CUA with a three-level priority scheme of "HIGH", "MEDIUM" and A CUA with a three-level priority scheme of "HIGH", "MEDIUM" and
"LOW" is mapped into this property such that a property value in the "LOW" is mapped into this property such that a property value in
range of one (US-ASCII decimal 49) to four (US-ASCII decimal 52) the range of one (US-ASCII decimal 49) to four (US-ASCII decimal
specifies "HIGH" priority. A value of five (US-ASCII decimal 53) is 52) specifies "HIGH" priority. A value of five (US-ASCII decimal
the normal or "MEDIUM" priority. A value in the range of six (US- 53) is the normal or "MEDIUM" priority. A value in the range of
ASCII decimal 54) to nine (US-ASCII decimal 58) is "LOW" priority. six (US- ASCII decimal 54) to nine (US-ASCII decimal 58) is "LOW"
priority.
A CUA with a priority schema of "A1", "A2", "A3", "B1", "B2", ..., A CUA with a priority schema of "A1", "A2", "A3", "B1", "B2", ...,
"C3" is mapped into this property such that a property value of one "C3" is mapped into this property such that a property value of
(US-ASCII decimal 49) specifies "A1", a property value of two (US- one (US-ASCII decimal 49) specifies "A1", a property value of two
ASCII decimal 50) specifies "A2", a property value of three (US-ASCII (US- ASCII decimal 50) specifies "A2", a property value of three
decimal 51) specifies "A3", and so forth up to a property value of 9 (US-ASCII decimal 51) specifies "A3", and so forth up to a
(US-ASCII decimal 58) specifies "C3". property value of 9 (US-ASCII decimal 58) specifies "C3".
Other integer values are reserved for future use. Other integer values are reserved for future use.
Within a "VEVENT" calendar component, this property specifies a Within a "VEVENT" calendar component, this property specifies a
priority for the event. This property may be useful when more than priority for the event. This property may be useful when more
one event is scheduled for a given time period. than one event is scheduled for a given time period.
Within a "VTODO" calendar component, this property specified a Within a "VTODO" calendar component, this property specified a
priority for the to-do. This property is useful in prioritizing priority for the to-do. This property is useful in prioritizing
multiple action items for a given time period. multiple action items for a given time period.
Format Definition: The property is specified by the following Format Definition: The property is defined by the following notation:
notation:
priority = "PRIORITY" prioparam ":" privalue CRLF priority = "PRIORITY" prioparam ":" privalue CRLF
;Default is zero ;Default is zero
prioparam = *(";" xparam) prioparam = *(";" xparam)
privalue = integer ;Must be in the range [0..9] privalue = integer ;Must be in the range [0..9]
; All other values are reserved for future use ; All other values are reserved for future use
The following is an example of a property with the highest priority: The following is an example of a property with the highest
priority:
PRIORITY:1 PRIORITY:1
The following is an example of a property with a next highest The following is an example of a property with a next highest
priority: priority:
PRIORITY:2 PRIORITY:2
Example: The following is an example of a property with no priority. Example: The following is an example of a property with no priority.
This is equivalent to not specifying the "PRIORITY" property: This is equivalent to not specifying the "PRIORITY" property:
PRIORITY:0 PRIORITY:0
8.2.10. Resources 3.8.1.10. Resources
Property Name: RESOURCES Property Name: RESOURCES
Purpose: This property defines the equipment or resources anticipated Purpose: This property defines the equipment or resources anticipated
for an activity specified by a calendar entity.. for an activity specified by a calendar entity..
Value Type: TEXT Value Type: TEXT
Property Parameters: Non-standard, alternate text representation and Property Parameters: Non-standard, alternate text representation and
language property parameters can be specified on this property. language property parameters can be specified on this property.
skipping to change at page 60, line 41 skipping to change at page 87, line 48
(";" xparam) (";" xparam)
) )
Example: The following is an example of this property: Example: The following is an example of this property:
RESOURCES:EASEL,PROJECTOR,VCR RESOURCES:EASEL,PROJECTOR,VCR
RESOURCES;LANGUAGE=fr:1 raton-laveur RESOURCES;LANGUAGE=fr:1 raton-laveur
8.2.11. Free/Busy Time Type 3.8.1.11. Status
Parameter Name: FBTYPE
Purpose: To specify the free or busy time type.
Description: The parameter specifies the free or busy time type. The
value FREE indicates that the time interval is free for scheduling.
The value BUSY indicates that the time interval is busy because one
or more events have been scheduled for that interval. The value
BUSY-UNAVAILABLE indicates that the time interval is busy and that
the interval can not be scheduled. The value BUSY-TENTATIVE
indicates that the time interval is busy because one or more events
have been tentatively scheduled for that interval. If not specified
on a property that allows this parameter, the default is BUSY.
Format Definition: The property parameter is defined by the following
notation:
fbtypeparam = "FBTYPE" "=" ("FREE" / "BUSY"
/ "BUSY-UNAVAILABLE" / "BUSY-TENTATIVE"
/ x-name
; Some experimental iCalendar data type.
/ iana-token)
; Some other IANA registered iCalendar data type.
Example: The following is an example of this parameter on a FREEBUSY
property.
FREEBUSY;FBTYPE=BUSY:19980415T133000Z/19980415T170000Z
8.2.12. Participation Status
Parameter Name: PARTSTAT
Purpose: To specify the participation status for the calendar user
specified by the property.
Description: This parameter can be specified on properties with a
CAL-ADDRESS value type. The parameter identifies the participation
status for the calendar user specified by the property value. The
parameter values differ depending on whether they are associated with
a group scheduled "VEVENT", "VTODO" or "VJOURNAL". The values MUST
match one of the values allowed for the given calendar component. If
not specified on a property that allows this parameter, the default
value is NEEDS-ACTION.
Format Definition: The property parameter is defined by the following
notation:
partstatparam = "PARTSTAT" "="
("NEEDS-ACTION" ; Event needs action
/ "ACCEPTED" ; Event accepted
/ "DECLINED" ; Event declined
/ "TENTATIVE" ; Event tentatively
; accepted
/ "DELEGATED" ; Event delegated
/ x-name ; Experimental status
/ iana-token) ; Other IANA registered
; status
; These are the participation statuses for a "VEVENT".
; Default is NEEDS-ACTION
partstatparam /= "PARTSTAT" "="
("NEEDS-ACTION" ; To-do needs action
/ "ACCEPTED" ; To-do accepted
/ "DECLINED" ; To-do declined
/ "TENTATIVE" ; To-do tentatively
; 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
partstatparam /= "PARTSTAT" "="
("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
Example:
ATTENDEE;PARTSTAT=DECLINED:MAILTO:jsmith@host.com
8.2.13. Status
Property Name: STATUS Property Name: STATUS
Purpose: This property defines the overall status or confirmation for Purpose: This property defines the overall status or confirmation for
the calendar component. the calendar component.
Value Type: TEXT Value Type: TEXT
Property Parameters: Non-standard property parameters can be Property Parameters: Non-standard property parameters can be
specified on this property. specified on this property.
Conformance: This property can be specified in "VEVENT", "VTODO" or Conformance: This property can be specified in "VEVENT", "VTODO" or
"VJOURNAL" calendar components. "VJOURNAL" calendar components.
Description: In a group scheduled calendar component, the property is Description: In a group scheduled calendar component, the property is
used by the "Organizer" to provide a confirmation of the event to the used by the "Organizer" to provide a confirmation of the event to
"Attendees". For example in a "VEVENT" calendar component, the the "Attendees". For example in a "VEVENT" calendar component,
"Organizer" can indicate that a meeting is tentative, confirmed or the "Organizer" can indicate that a meeting is tentative,
cancelled. In a "VTODO" calendar component, the "Organizer" can confirmed or cancelled. In a "VTODO" calendar component, the
indicate that an action item needs action, is completed, is in "Organizer" can indicate that an action item needs action, is
process or being worked on, or has been cancelled. In a "VJOURNAL" completed, is in process or being worked on, or has been
calendar component, the "Organizer" can indicate that a journal entry cancelled. In a "VJOURNAL" calendar component, the "Organizer"
is draft, final or has been cancelled or removed. can indicate that a journal entry is draft, final or has been
cancelled or removed.
Format Definition: The property is defined by the following notation: Format Definition: The property is defined by the following notation:
status = "STATUS" statparam] ":" statvalue CRLF status = "STATUS" statparam] ":" statvalue CRLF
statparam = *(";" xparam) statparam = *(";" xparam)
statvalue = "TENTATIVE" ;Indicates event is statvalue = "TENTATIVE" ;Indicates event is
;tentative. ;tentative.
/ "CONFIRMED" ;Indicates event is / "CONFIRMED" ;Indicates event is
skipping to change at page 64, line 35 skipping to change at page 89, line 10
statvalue =/ "DRAFT" ;Indicates journal is draft. statvalue =/ "DRAFT" ;Indicates journal is draft.
/ "FINAL" ;Indicates journal is final. / "FINAL" ;Indicates journal is final.
/ "CANCELLED" ;Indicates journal is removed. / "CANCELLED" ;Indicates journal is removed.
;Status values for "VJOURNAL". ;Status values for "VJOURNAL".
Example: The following is an example of this property for a "VEVENT" Example: The following is an example of this property for a "VEVENT"
calendar component: calendar component:
STATUS:TENTATIVE STATUS:TENTATIVE
The following is an example of this property for a "VTODO" calendar The following is an example of this property for a "VTODO"
component: calendar component:
STATUS:NEEDS-ACTION STATUS:NEEDS-ACTION
The following is an example of this property for a "VJOURNAL" The following is an example of this property for a "VJOURNAL"
calendar component: calendar component:
STATUS:DRAFT STATUS:DRAFT
8.2.14. Summary 3.8.1.12. Summary
Property Name: SUMMARY Property Name: SUMMARY
Purpose: This property defines a short summary or subject for the Purpose: This property defines a short summary or subject for the
calendar component. calendar component.
Value Type: TEXT Value Type: TEXT
Property Parameters: Non-standard, alternate text representation and Property Parameters: Non-standard, alternate text representation and
language property parameters can be specified on this property. language property parameters can be specified on this property.
Conformance: The property can be specified in "VEVENT", "VTODO", Conformance: The property can be specified in "VEVENT", "VTODO",
"VJOURNAL" or "VALARM" calendar components. "VJOURNAL" or "VALARM" calendar components.
Description: This property is used in the "VEVENT", "VTODO" and Description: This property is used in the "VEVENT", "VTODO" and
"VJOURNAL" calendar components to capture a short, one line summary "VJOURNAL" calendar components to capture a short, one line
about the activity or journal entry. summary about the activity or journal entry.
This property is used in the "VALARM" calendar component to capture This property is used in the "VALARM" calendar component to
the subject of an EMAIL category of alarm. capture the subject of an EMAIL category of alarm.
Format Definition: The property is defined by the following notation: Format Definition: The property is defined by the following notation:
summary = "SUMMARY" summparam ":" text CRLF summary = "SUMMARY" summparam ":" text CRLF
summparam = *( summparam = *(
; the following are optional, ; the following are optional,
; but MUST NOT occur more than once ; but MUST NOT occur more than once
skipping to change at page 65, line 39 skipping to change at page 90, line 25
; and MAY occur more than once ; and MAY occur more than once
(";" xparam) (";" xparam)
) )
Example: The following is an example of this property: Example: The following is an example of this property:
SUMMARY:Department Party SUMMARY:Department Party
8.2.15. Date and Time Component Properties 3.8.2. Date and Time Component Properties
The following properties specify date and time related information in The following properties specify date and time related information in
calendar components. calendar components.
8.2.15.1. Date/Time Completed 3.8.2.1. Date/Time Completed
Property Name: COMPLETED Property Name: COMPLETED
Purpose: This property defines the date and time that a to-do was Purpose: This property defines the date and time that a to-do was
actually completed. actually completed.
Value Type: DATE-TIME Value Type: DATE-TIME
Property Parameters: Non-standard property parameters can be Property Parameters: Non-standard property parameters can be
specified on this property. specified on this property.
Conformance: The property can be specified in a "VTODO" calendar Conformance: The property can be specified in a "VTODO" calendar
component. component.
Description: The date and time MUST be in a UTC format. Description: The date and time MUST be in a UTC format.
Format Definition: The property is defined by the following notation: Format Definition: The property is defined by the following notation:
skipping to change at page 66, line 17 skipping to change at page 91, line 4
Conformance: The property can be specified in a "VTODO" calendar Conformance: The property can be specified in a "VTODO" calendar
component. component.
Description: The date and time MUST be in a UTC format. Description: The date and time MUST be in a UTC format.
Format Definition: The property is defined by the following notation: Format Definition: The property is defined by the following notation:
completed = "COMPLETED" compparam ":" date-time CRLF completed = "COMPLETED" compparam ":" date-time CRLF
compparam = *(";" xparam) compparam = *(";" xparam)
Example: The following is an example of this property: Example: The following is an example of this property:
COMPLETED:19960401T235959Z COMPLETED:19960401T235959Z
8.2.15.2. Date/Time End 3.8.2.2. Date/Time End
Property Name: DTEND Property Name: DTEND
Purpose: This property specifies the date and time that a calendar Purpose: This property specifies the date and time that a calendar
component ends. component ends.
Value Type: The default value type is DATE-TIME. The value type can Value Type: The default value type is DATE-TIME. The value type can
be set to a DATE value type. be set to a DATE value type.
Property Parameters: Non-standard, value data type, time zone Property Parameters: Non-standard, value data type, time zone
identifier property parameters can be specified on this property. identifier property parameters can be specified on this property.
Conformance: This property can be specified in "VEVENT" or Conformance: This property can be specified in "VEVENT" or
"VFREEBUSY" calendar components. "VFREEBUSY" calendar components.
Description: Within the "VEVENT" calendar component, this property Description: Within the "VEVENT" calendar component, this property
defines the date and time by which the event ends. The value MUST be defines the date and time by which the event ends. The value MUST
later in time than the value of the "DTSTART" property. be later in time than the value of the "DTSTART" property.
Within the "VFREEBUSY" calendar component, this property defines the Within the "VFREEBUSY" calendar component, this property defines
end date and time for the free or busy time information. The time the end date and time for the free or busy time information. The
MUST be specified in the UTC time format. The value MUST be later in time MUST be specified in the UTC time format. The value MUST be
time than the value of the "DTSTART" property. later in time than the value of the "DTSTART" property.
Format Definition: The property is defined by the following notation: Format Definition: The property is defined by the following notation:
dtend = "DTEND" dtendparam":" dtendval CRLF dtend = "DTEND" dtendparam":" dtendval CRLF
dtendparam = *( dtendparam = *(
; the following are optional, ; the following are optional,
; but MUST NOT occur more than once ; but MUST NOT occur more than once
skipping to change at page 67, line 33 skipping to change at page 92, line 31
dtendval = date-time / date dtendval = date-time / date
;Value MUST match value type ;Value MUST match value type
Example: The following is an example of this property: Example: The following is an example of this property:
DTEND:19960401T235959Z DTEND:19960401T235959Z
DTEND;VALUE=DATE:19980704 DTEND;VALUE=DATE:19980704
8.2.15.3. Date/Time Due 3.8.2.3. Date/Time Due
Property Name: DUE Property Name: DUE
Purpose: This property defines the date and time that a to-do is Purpose: This property defines the date and time that a to-do is
expected to be completed. expected to be completed.
Value Type: The default value type is DATE-TIME. The value type can Value Type: The default value type is DATE-TIME. The value type can
be set to a DATE value type. be set to a DATE value type.
Property Parameters: Non-standard, value data type, time zone Property Parameters: Non-standard, value data type, time zone
skipping to change at page 68, line 30 skipping to change at page 93, line 30
) )
dueval = date-time / date dueval = date-time / date
;Value MUST match value type ;Value MUST match value type
Example: The following is an example of this property: Example: The following is an example of this property:
DUE:19980430T235959Z DUE:19980430T235959Z
8.2.15.4. Date/Time Start 3.8.2.4. Date/Time Start
Property Name: DTSTART Property Name: DTSTART
Purpose: This property specifies when the calendar component begins. Purpose: This property specifies when the calendar component begins.
Value Type: The default value type is DATE-TIME. The time value MUST Value Type: The default value type is DATE-TIME. The time value MUST
be one of the forms defined for the DATE-TIME value type. The value be one of the forms defined for the DATE-TIME value type. The
type can be set to a DATE value type. value type can be set to a DATE value type.
Property Parameters: Non-standard, value data type, time zone Property Parameters: Non-standard, value data type, time zone
identifier property parameters can be specified on this property. identifier property parameters can be specified on this property.
Conformance: This property can be specified in the "VEVENT", "VTODO", Conformance: This property can be specified in the "VEVENT", "VTODO",
"VFREEBUSY", or "VTIMEZONE" calendar components. "VFREEBUSY", or "VTIMEZONE" calendar components.
Description: Within the "VEVENT" calendar component, this property Description: Within the "VEVENT" calendar component, this property
defines the start date and time for the event. The property is defines the start date and time for the event. The property is
REQUIRED in "VEVENT" calendar components. Events can have a start REQUIRED in "VEVENT" calendar components. Events can have a start
date/time but no end date/time. In that case, the event does not date/time but no end date/time. In that case, the event does not
take up any time. take up any time.
Within the "VFREEBUSY" calendar component, this property defines the Within the "VFREEBUSY" calendar component, this property defines
start date and time for the free or busy time information. The time the start date and time for the free or busy time information.
MUST be specified in UTC time. The time MUST be specified in UTC time.
Within the "VTIMEZONE" calendar component, this property defines the Within the "VTIMEZONE" calendar component, this property defines
effective start date and time for a time zone specification. This the effective start date and time for a time zone specification.
property is REQUIRED within each STANDARD and DAYLIGHT part included This property is REQUIRED within each STANDARD and DAYLIGHT part
in "VTIMEZONE" calendar components and MUST be specified as a local included in "VTIMEZONE" calendar components and MUST be specified
DATE-TIME without the "TZID" property parameter. as a local DATE-TIME without the "TZID" property parameter.
Format Definition: The property is defined by the following notation: Format Definition: The property is defined by the following notation:
dtstart = "DTSTART" dtstparam ":" dtstval CRLF dtstart = "DTSTART" dtstparam ":" dtstval CRLF
dtstparam = *( dtstparam = *(
; the following are optional, ; the following are optional,
; but MUST NOT occur more than once ; but MUST NOT occur more than once
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) )
dtstval = date-time / date dtstval = date-time / date
;Value MUST match value type ;Value MUST match value type
Example: The following is an example of this property: Example: The following is an example of this property:
DTSTART:19980118T073000Z DTSTART:19980118T073000Z
8.2.15.5. Duration 3.8.2.5. Duration
Property Name: DURATION Property Name: DURATION
Purpose: The property specifies a positive duration of time. Purpose: The property specifies a positive duration of time.
Value Type: DURATION Value Type: DURATION
Property Parameters: Non-standard property parameters can be Property Parameters: Non-standard property parameters can be
specified on this property. specified on this property.
Conformance: The property can be specified in "VEVENT", "VTODO", Conformance: The property can be specified in "VEVENT", "VTODO",
"VFREEBUSY" or "VALARM" calendar components. "VFREEBUSY" or "VALARM" calendar components.
Description: In a "VEVENT" calendar component the property may be Description: In a "VEVENT" calendar component the property may be
used to specify a duration of the event, instead of an explicit end used to specify a duration of the event, instead of an explicit
date/time. In a "VTODO" calendar component the property may be used end date/time. In a "VTODO" calendar component the property may
to specify a duration for the to-do, instead of an explicit due date/ be used to specify a duration for the to-do, instead of an
time. In a "VFREEBUSY" calendar component the property may be used explicit due date/time. In a "VFREEBUSY" calendar component the
to specify the interval of free time being requested. In a "VALARM" property may be used to specify the interval of free time being
calendar component the property may be used to specify the delay requested. In a "VALARM" calendar component the property may be
period prior to repeating an alarm. used to specify the delay period prior to repeating an alarm.
Format Definition: The property is defined by the following notation: Format Definition: The property is defined by the following notation:
duration = "DURATION" durparam ":" dur-value CRLF duration = "DURATION" durparam ":" dur-value CRLF
;consisting of a positive duration of time. ;consisting of a positive duration of time.
durparam = *(";" xparam) durparam = *(";" xparam)
Example: The following is an example of this property that specifies Example: The following is an example of this property that specifies
an interval of time of 1 hour and zero minutes and zero seconds: an interval of time of 1 hour and zero minutes and zero seconds:
DURATION:PT1H0M0S DURATION:PT1H0M0S
The following is an example of this property that specifies an The following is an example of this property that specifies an
interval of time of 15 minutes. interval of time of 15 minutes.
DURATION:PT15M DURATION:PT15M
8.2.15.6. Free/Busy Time 3.8.2.6. Free/Busy Time
Property Name: FREEBUSY Property Name: FREEBUSY
Purpose: The property defines one or more free or busy time Purpose: The property defines one or more free or busy time
intervals. intervals.
Value Type: PERIOD. The date and time values MUST be in an UTC time Value Type: PERIOD. The date and time values MUST be in an UTC time
format. format.
Property Parameters: Non-standard or free/busy time type property Property Parameters: Non-standard or free/busy time type property
parameters can be specified on this property. parameters can be specified on this property.
Conformance: The property can be specified in a "VFREEBUSY" calendar Conformance: The property can be specified in a "VFREEBUSY" calendar
component. component.
Property Parameter: "FBTYPE" and non-standard parameters can be
specified on this property.
Description: These time periods can be specified as either a start Description: These time periods can be specified as either a start
and end date-time or a start date-time and duration. The date and and end date-time or a start date-time and duration. The date and
time MUST be a UTC time format. time MUST be a UTC time format.
"FREEBUSY" properties within the "VFREEBUSY" calendar component "FREEBUSY" properties within the "VFREEBUSY" calendar component
SHOULD be sorted in ascending order, based on start time and then end SHOULD be sorted in ascending order, based on start time and then
time, with the earliest periods first. end time, with the earliest periods first.
The "FREEBUSY" property can specify more than one value, separated by The "FREEBUSY" property can specify more than one value, separated
the COMMA character (US-ASCII decimal 44). In such cases, the by the COMMA character (US-ASCII decimal 44). In such cases, the
"FREEBUSY" property values SHOULD all be of the same "FBTYPE" "FREEBUSY" property values SHOULD all be of the same "FBTYPE"
property parameter type (e.g., all values of a particular "FBTYPE" property parameter type (e.g., all values of a particular "FBTYPE"
listed together in a single property). listed together in a single property).
Format Definition: The property is defined by the following notation: Format Definition: The property is defined by the following notation:
freebusy = "FREEBUSY" fbparam ":" fbvalue freebusy = "FREEBUSY" fbparam ":" fbvalue
CRLF CRLF
fbparam = *( fbparam = *(
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Example: The following are some examples of this property: Example: The following are some examples of this property:
FREEBUSY;FBTYPE=BUSY-UNAVAILABLE:19970308T160000Z/PT8H30M FREEBUSY;FBTYPE=BUSY-UNAVAILABLE:19970308T160000Z/PT8H30M
FREEBUSY;FBTYPE=FREE:19970308T160000Z/PT3H,19970308T200000Z/PT1H FREEBUSY;FBTYPE=FREE:19970308T160000Z/PT3H,19970308T200000Z/PT1H
FREEBUSY;FBTYPE=FREE:19970308T160000Z/PT3H,19970308T200000Z/PT1H, FREEBUSY;FBTYPE=FREE:19970308T160000Z/PT3H,19970308T200000Z/PT1H,
19970308T230000Z/19970309T000000Z 19970308T230000Z/19970309T000000Z
8.2.15.7. Time Transparency 3.8.2.7. Time Transparency
Property Name: TRANSP Property Name: TRANSP
Purpose: This property defines whether an event is transparent or not Purpose: This property defines whether an event is transparent or not
to busy time searches. to busy time searches.
Value Type: TEXT Value Type: TEXT
Property Parameters: Non-standard property parameters can be Property Parameters: Non-standard property parameters can be
specified on this property. specified on this property.
Conformance: This property can be specified once in a "VEVENT" Conformance: This property can be specified once in a "VEVENT"
calendar component. calendar component.
Description: Time Transparency is the characteristic of an event that Description: Time Transparency is the characteristic of an event that
determines whether it appears to consume time on a calendar. Events determines whether it appears to consume time on a calendar.
that consume actual time for the individual or resource associated Events that consume actual time for the individual or resource
associated with the calendar SHOULD be recorded as OPAQUE,
with the calendar SHOULD be recorded as OPAQUE, allowing them to be allowing them to be detected by free-busy time searches. Other
detected by free-busy time searches. Other events, which do not take events, which do not take up the individual's (or resource's) time
up the individual's (or resource's) time SHOULD be recorded as SHOULD be recorded as TRANSPARENT, making them invisible to free-
TRANSPARENT, making them invisible to free-busy time searches. busy time searches.
Format Definition: The property is specified by the following Format Definition: The property is defined by the following notation:
notation:
transp = "TRANSP" tranparam ":" transvalue CRLF transp = "TRANSP" tranparam ":" transvalue CRLF
tranparam = *(";" xparam) tranparam = *(";" xparam)
transvalue = "OPAQUE" ;Blocks or opaque on busy time searches. transvalue = "OPAQUE" ;Blocks or opaque on busy time searches.
/ "TRANSPARENT" ;Transparent on busy time searches. / "TRANSPARENT" ;Transparent on busy time searches.
;Default value is OPAQUE ;Default value is OPAQUE
Example: The following is an example of this property for an event Example: The following is an example of this property for an event
that is transparent or does not block on free/busy time searches: that is transparent or does not block on free/busy time searches:
TRANSP:TRANSPARENT TRANSP:TRANSPARENT
The following is an example of this property for an event that is The following is an example of this property for an event that is
opaque or blocks on free/busy time searches: opaque or blocks on free/busy time searches:
TRANSP:OPAQUE TRANSP:OPAQUE
8.2.16. Time Zone Component Properties 3.8.3. Time Zone Component Properties
The following properties specify time zone information in calendar The following properties specify time zone information in calendar
components. components.
8.2.16.1. Time Zone Identifier 3.8.3.1. Time Zone Identifier
Property Name: TZID Property Name: TZID
Purpose: This property specifies the text value that uniquely Purpose: This property specifies the text value that uniquely
identifies the "VTIMEZONE" calendar component. identifies the "VTIMEZONE" calendar component.
Value Type: TEXT Value Type: TEXT
Property Parameters: Non-standard property parameters can be Property Parameters: Non-standard property parameters can be
specified on this property. specified on this property.
Conformance: This property MUST be specified in a "VTIMEZONE" Conformance: This property MUST be specified in a "VTIMEZONE"
calendar component. calendar component.
Description: This is the label by which a time zone calendar Description: This is the label by which a time zone calendar
component is referenced by any iCalendar properties whose data type component is referenced by any iCalendar properties whose data
is either DATE-TIME or TIME and not intended to specify a UTC or a type is either DATE-TIME or TIME and not intended to specify a UTC
"floating" time. The presence of the SOLIDUS character (US-ASCII or a "floating" time. The presence of the SOLIDUS character (US-
decimal 47) as a prefix, indicates that this TZID represents an ASCII decimal 47) as a prefix, indicates that this TZID represents
unique ID in a globally defined time zone registry (when such an unique ID in a globally defined time zone registry (when such
registry is defined). registry is defined).
Note: This document does not define a naming convention for time zone Note: This document does not define a naming convention for
identifiers. Implementers may want to use the naming conventions time zone identifiers. Implementers may want to use the naming
defined in existing time zone specifications such as the public- conventions defined in existing time zone specifications such
domain Olson database [TZ]. The specification of globally unique as the public-domain Olson database [TZDB]. The specification
time zone identifiers is not addressed by this document and is left of globally unique time zone identifiers is not addressed by
for future study. this document and is left for future study.
Format Definition: This property is defined by the following Format Definition: The property is defined by the following notation:
notation:
tzid = "TZID" tzidpropparam ":" [tzidprefix] text CRLF tzid = "TZID" tzidpropparam ":" [tzidprefix] text CRLF
tzidpropparam = *(";" xparam) tzidpropparam = *(";" xparam)
;tzidprefix = "/" ;tzidprefix = "/"
; Defined previously. Just listed here for reader convenience. ; Defined previously. Just listed here for reader convenience.
Example: The following are examples of non-globally unique time zone Example: The following are examples of non-globally unique time zone
identifiers: identifiers:
TZID:US-Eastern TZID:US-Eastern
TZID:California-Los_Angeles TZID:California-Los_Angeles
The following is an example of a fictitious globally unique time
The following is an example of a fictitious globally unique time zone zone identifier:
identifier:
TZID:/US-New_York-New_York TZID:/US-New_York-New_York
8.2.16.2. Time Zone Name 3.8.3.2. Time Zone Name
Property Name: TZNAME Property Name: TZNAME
Purpose: This property specifies the customary designation for a time Purpose: This property specifies the customary designation for a time
zone description. zone description.
Value Type: TEXT Value Type: TEXT
Property Parameters: Non-standard and language property parameters Property Parameters: Non-standard and language property parameters
can be specified on this property. can be specified on this property.
Conformance: This property can be specified in a "VTIMEZONE" calendar Conformance: This property can be specified in a "VTIMEZONE" calendar
component. component.
Description: This property may be specified in multiple languages; in Description: This property may be specified in multiple languages; in
order to provide for different language requirements. order to provide for different language requirements.
Format Definition: This property is defined by the following Format Definition: The property is defined by the following notation:
notation:
tzname = "TZNAME" tznparam ":" text CRLF tzname = "TZNAME" tznparam ":" text CRLF
tznparam = *( tznparam = *(
; the following is optional, ; the following is optional,
; but MUST NOT occur more than once ; but MUST NOT occur more than once
(";" languageparam) / (";" languageparam) /
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; 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
(";" xparam) (";" xparam)
) )
Example: The following are example of this property: Example: The following are example of this property:
TZNAME:EST TZNAME:EST
Figure 97
The following is an example of this property when two different The following is an example of this property when two different
languages for the time zone name are specified: languages for the time zone name are specified:
TZNAME;LANGUAGE=en:EST TZNAME;LANGUAGE=en:EST
TZNAME;LANGUAGE=fr-CA:HNE TZNAME;LANGUAGE=fr-CA:HNE
8.2.16.3. Time Zone Offset From 3.8.3.3. Time Zone Offset From
Property Name: TZOFFSETFROM Property Name: TZOFFSETFROM
Purpose: This property specifies the offset which is in use prior to Purpose: This property specifies the offset which is in use prior to
this time zone observance. this time zone observance.
Value Type: UTC-OFFSET Value Type: UTC-OFFSET
Property Parameters: Non-standard property parameters can be Property Parameters: Non-standard property parameters can be
specified on this property. specified on this property.
Conformance: This property MUST be specified in a "VTIMEZONE" Conformance: This property MUST be specified in a "VTIMEZONE"
calendar component. calendar component.
Description: This property specifies the offset which is in use prior Description: This property specifies the offset which is in use prior
to this time observance. It is used to calculate the absolute time to this time observance. It is used to calculate the absolute
at which the transition to a given observance takes place. This time at which the transition to a given observance takes place.
property MUST only be specified in a "VTIMEZONE" calendar component. This property MUST only be specified in a "VTIMEZONE" calendar
A "VTIMEZON