Network Working Group C. Daboo
Internet-Draft Apple
Intended status: Standards Track B. Desruisseaux
Expires: May 7, 2009 Oracle
November 3, 2008
Calendar Availability
draft-daboo-calendar-availability-01
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Abstract
This document specifies a new iCalendar calendar component that
allows the publication of available and unavailable time periods
associated with a calendar user. This component can be used in
standard iCalendar free-busy lookups, including iTIP free-busy
requests, to generate repeating blocks of available or busy time with
exceptions as needed.
This document also defines extensions to CalDAV calendar-access and
calendar-auto-schedule which specify how this new calendar component
should be used when doing free busy time evaluation in CalDAV.
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Editorial Note (To be removed by RFC Editor before publication)
Discussion of this specification is taking place on the mailing list
http://lists.osafoundation.org/mailman/listinfo/ietf-caldav.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Conventions Used in This Document . . . . . . . . . . . . . . 3
3. iCalendar Extensions . . . . . . . . . . . . . . . . . . . . . 4
3.1. Availability Component . . . . . . . . . . . . . . . . . . 4
3.2. Busy Time Type . . . . . . . . . . . . . . . . . . . . . . 8
4. Calculating Free-Busy Time . . . . . . . . . . . . . . . . . . 9
4.1. Examples . . . . . . . . . . . . . . . . . . . . . . . . . 10
5. CalDAV Extensions . . . . . . . . . . . . . . . . . . . . . . 11
5.1. CalDAV Requirements Overview . . . . . . . . . . . . . . . 11
5.2. New features in CalDAV . . . . . . . . . . . . . . . . . . 12
6. Security Considerations . . . . . . . . . . . . . . . . . . . 15
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
7.1. Component Registrations . . . . . . . . . . . . . . . . . 15
7.2. Property Registrations . . . . . . . . . . . . . . . . . . 15
8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 16
9. Normative References . . . . . . . . . . . . . . . . . . . . . 16
Appendix A. Example Calendar #1 . . . . . . . . . . . . . . . . . 16
Appendix B. Change History (To be removed by RFC Editor
before publication) . . . . . . . . . . . . . . . . . 18
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 18
Intellectual Property and Copyright Statements . . . . . . . . . . 19
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1. Introduction
Often calendar users have regular periods of time when they are
either available to be scheduled or always unavailable. For example,
an office worker will often wish to only appear free to their work
colleagues during normal 'office hours' (e.g., Monday through Friday,
9 am through 5 pm). Or, a university professor may only be available
to students during a set period of time (e.g., Thursday afternoons, 2
pm through 5 pm during term time only). Ideally users should be able
to specify such periods directly via their calendar user agent, and
have them automatically considered as part of the normal free-busy
lookup for that user. In addition it should be possible for
different periods of available time to appear for different users.
However, iCalendar [I-D.ietf-calsify-rfc2445bis] does not provide a
way to specify a repeating period of available or unavailable time as
"VFREEBUSY" components cannot include any form of recurrence
information, as opposed to "VEVENT" components which can. Since
repeating patterns are often the case, "VFREEBUSY" components are not
sufficient to solve this problem.
This specification defines a new type of iCalendar calendar component
that can be used to publish user availability.
CalDAV [RFC4791] provides a way for calendar users to access and
manage calendar data and exchange this data via scheduling
operations. As part of this the CalDAV calendar-access [RFC4791]
feature provides a CALDAV:free-busy-query REPORT that returns free-
busy information for a calendar collection or hierarchy of calendar
collections. Also, the CalDAV calendar-auto-schedule
[I-D.desruisseaux-caldav-sched] feature allows free-busy information
for a calendar user to be determined. Both of these operations
involve examining user calendars for events that 'block time', with
the blocked out periods being returned in a "VFREEBUSY" component.
This specification extends the CalDAV calendar-access and CalDAV
calendar-auto-schedule features to allow the new iCalendar
availability components to be stored and manipulated, and to allow
free-busy lookups to use the information from any such components, if
present.
2. Conventions Used in This Document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
[RFC2119].
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When XML element types in the namespaces "DAV:" and
"urn:ietf:params:xml:ns:caldav" are referenced in this document
outside of the context of an XML fragment, the string "DAV:" and
"CALDAV:" will be prefixed to the element type names respectively.
3. iCalendar Extensions
This specification adds a new "VAVAILABILITY" calendar component to
iCalendar. The "VAVAILABILITY" component is itself a container for
new "AVAILABLE" sub-components.
The purpose of the "VAVAILABILITY" calendar component is to provide a
grouping of available time information over a specific range of time.
Within that there are specific time ranges that are marked as
available via a set of "AVAILABLE" calendar sub-components. Together
these can be used to specify available time that can repeat over set
periods of time, and which can vary over time.
3.1. Availability Component
Component Name: VAVAILABILITY
Purpose: Provide a grouping of component properties that describe
the availability associated with a calendar user.
Format Definition: A "VAVAILABILITY" calendar component is defined
by the following notation:
availabilityc = "BEGIN" ":" "VAVAILABILITY" CRLF
availabilityprop *availablec
"END" ":" "VAVAILABILITY" CRLF
availabilityprop = *(
; the following are REQUIRED,
; but MUST NOT occur more than once
dtstamp / uid
; the following are OPTIONAL,
; but MUST NOT occur more than once
busytype / created / dtend /dtstart /
last-mod / organizer / seq / summary / url /
; 'duration' is OPTIONAL in a
; 'availabilityprop' but MUST only be
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; present if 'dtstart' is also present and
; 'dtend' is not present, and it MUST NOT
; occur more than once
duration /
; the following are OPTIONAL,
; and MAY occur more than once
categories / comment / contact / x-prop
)
availablec = "BEGIN" ":" "AVAILABLE" CRLF
availableprop
"END" ":" "AVAILABLE" CRLF
availableprop = *(
; the following are REQUIRED,
; but MUST NOT occur more than once
dtstamp / dtstart / uid /
; either a 'dtend' or a 'duration' is REQUIRED
; in a 'availableprop', but 'dtend' and
; 'duration' MUST NOT occur in the same
; 'availableprop', and each MUST NOT occur more
; than once
dtend / duration /
; the following are OPTIONAL,
; but MUST NOT occur more than once
created / last-mod / recurid / rrule /
summary /
; the following are OPTIONAL,
; and MAY occur more than once
categories / comment / contact / exdate /
rdate / x-prop
)
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Description: A "VAVAILABILITY" component indicates a period of time
within which availability information is provided. A
"VAVAILABILITY" component MUST specify a start time and optionally
an end time or duration. Within that time period, availability
defaults to a free-busy type of "BUSY-UNAVAILABLE", except for any
time periods corresponding to "AVAILABLE" sub-components.
"AVAILABLE" sub-components are used to indicate periods of free
time within the time range of the enclosing "VAVAILABILITY"
component. "AVAILABLE" sub-components MAY include recurrence
properties to specify recurring periods of time, which may be
overridden using normal recurrence behavior (i.e., use of the
"RECURRENCE-ID" property).
If specified, the "DTSTART" and "DTEND" properties in
"VAVAILABILITY" components and "AVAILABLE" sub-components MUST be
"DATE-TIME" values specified as either date with UTC time or date
with local time and a time zone reference.
If any property with a "DATE-TIME" value is present in a
"VAVAILABILITY" component or any of its "AVAILABLE" sub-
components, and that property includes a "TZID" parameter, then
the iCalendar object containing the "VAVAILABILITY" component MUST
contain "VTIMEZONE" components corresponding to each unique "TZID"
parameter value.
When used to publish available time, the "ORGANIZER" property
specifies the calendar user associated with the published
available time.
Example: The following is an example of a "VAVAILABILITY" calendar
component used to represent the availability of a user available
Monday through Friday, 9:00 AM to 5:00 PM in the America/Montreal
time zone:
BEGIN:VAVAILABILITY
ORGANIZER:mailto:bernard@example.com
UID:20061005T133225Z-00001@example.com
DTSTAMP:20061005T133225Z
DTSTART;TZID=America/Montreal:20061002T000000
BEGIN:AVAILABLE
UID:20061005T133225Z-00001-A@example.com
SUMMARY:Monday to Friday from 9:00 to 17:00
DTSTART;TZID=America/Montreal:20061002T090000
DTEND;TZID=America/Montreal:20061002T170000
RRULE:FREQ=WEEKLY;BYDAY=MO,TU,WE,TH,FR
END:AVAILABLE
END:VAVAILABILITY
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The following is an example of a "VAVAILABILITY" calendar
component used to represent the availability of a user available
Monday through Thursday, 9:00 AM to 5:00 PM, and Friday 9:00 AM to
12:00 PM in the America/Montreal time zone:
BEGIN:VAVAILABILITY
ORGANIZER:mailto:bernard@example.com
UID:20061005T133225Z-00001@example.com
DTSTAMP:20061005T133225Z
DTSTART;TZID=America/Montreal:20061002T000000
DTEND;TZID=America/Montreal:20061202T000000
BEGIN:AVAILABLE
UID:20061005T133225Z-00001-A@example.com
SUMMARY:Monday to Thursday from 9:00 to 17:00
DTSTART;TZID=America/Montreal:20061002T090000
DTEND;TZID=America/Montreal:20061002T170000
RRULE:FREQ=WEEKLY;BYDAY=MO,TU,WE,TH
END:AVAILABLE
BEGIN:AVAILABLE
UID:20061005T133225Z-00001-B@example.com
SUMMARY:Friday from 9:00 to 12:00
DTSTART;TZID=America/Montreal:20061006T090000
DTEND;TZID=America/Montreal:20061006T120000
RRULE:FREQ=WEEKLY;BYDAY=FR
END:AVAILABLE
END:VAVAILABILITY
The following is an example of three "VAVAILABILITY" calendar
components used to represent the availability of an itinerant
worker: Monday through Friday, 9:00 AM to 5:00 PM each day.
However, for three weeks the calendar user is working in Montreal,
then one week in Los Angeles, then back to Montreal. Note that
each overall period is covered by separate "VAVAILABILITY"
components. The last of these has no DTEND so continues on "for
ever". This example shows how "exceptions" to available time can
be handled.
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BEGIN:VAVAILABILITY
ORGANIZER:mailto:bernard@example.com
UID:20061005T133225Z-00001@example.com
DTSTAMP:20061005T133225Z
DTSTART;TZID=America/Montreal:20061002T000000
DTEND;TZID=America/Montreal:20061023T030000
BEGIN:AVAILABLE
UID:20061005T133225Z-00001-A@example.com
SUMMARY:Monday to Friday from 9:00 to 17:00
DTSTART;TZID=America/Montreal:20061002T090000
DTEND;TZID=America/Montreal:20061002T170000
RRULE:FREQ=WEEKLY;BYDAY=MO,TU,WE,TH,FR
END:AVAILABLE
END:VAVAILABILITY
BEGIN:VAVAILABILITY
ORGANIZER:mailto:bernard@example.com
UID:20061005T133225Z-00001@example.com
DTSTAMP:20061005T133225Z
DTSTART;TZID=America/Los_Angeles:20061023T000000
DTEND;TZID=America/Los_Angeles:20061030T000000
BEGIN:AVAILABLE
UID:20061005T133225Z-00001-A@example.com
SUMMARY:Monday to Friday from 9:00 to 17:00
DTSTART;TZID=America/Los_Angeles:20061023T090000
DTEND;TZID=America/Los_Angeles:20061023T170000
RRULE:FREQ=WEEKLY;BYDAY=MO,TU,WE,TH,FR
END:AVAILABLE
END:VAVAILABILITY
BEGIN:VAVAILABILITY
ORGANIZER:mailto:bernard@example.com
UID:20061005T133225Z-00001@example.com
DTSTAMP:20061005T133225Z
DTSTART;TZID=America/Montreal:20061030T030000
BEGIN:AVAILABLE
UID:20061005T133225Z-00001-A@example.com
SUMMARY:Monday to Friday from 9:00 to 17:00
DTSTART;TZID=America/Montreal:20061030T090000
DTEND;TZID=America/Montreal:20061030T170000
RRULE:FREQ=WEEKLY;BYDAY=MO,TU,WE,TH,FR
END:AVAILABLE
END:VAVAILABILITY
3.2. Busy Time Type
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Property Name: BUSYTYPE
Purpose: This property specifies the default busy time type.
Value Type: TEXT
Property Parameters: Non-standard property parameters can be
specified on this property.
Conformance: This property can be specified within "VAVAILABILITY"
calendar components.
Format Definition: This property is defined by the following
notation:
busytype = "BUSYTYPE" busytypeparam ":" busytypevalue CRLF
busytypeparam = *(";" xparam)
busytypevalue = "BUSY" / "BUSY-UNAVAILABLE" /
"BUSY-TENTATIVE" / iana-token / x-name
; Default is "BUSY-UNAVAILABLE"
Description: This property is used to specify the default busy time
type. The values correspond to those used by the "FBTYPE"
parameter used on a "FREEBUSY" property, with the exception that
the "FREE" value is not used. If not specified on a component
that allows this property, the default is "BUSY-UNAVAILABLE".
Example: The following is an example of this property:
BUSYTYPE:BUSY
4. Calculating Free-Busy Time
This section describes how free-busy time information for a calendar
user is calculated in the presence of "VAVAILABILITY" calendar
components.
An iCalendar "VFREEBUSY" component is used to convey "rolled-up"
free-busy time information for a calendar user. This can be
generated as the result of an iTIP "VFREEBUSY"
[I-D.ietf-calsify-2446bis] request or through some other mechanism
(e.g., a CalDAV calendar-access CALDAV:free-busy-query REPORT).
When a "VAVAILABILITY" component is present and intersects the time-
range for the free-busy request, the time covered by the
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"VAVAILABILITY" component is set to busy and then portions of it
"carved out" to be free based on the "AVAILABLE" components in the
"VAVAILABILITY" component. Once that is done, regular "VEVENT" and
"VFREEBUSY" components can be "overlaid" in the usual way to block
out additional time.
An example procedure for this is as follows:
1. Initially mark the entire period of the free-busy request as
free.
2. For each "VAVAILABILITY" component:
1. Determine if the "VAVAILABILITY" intersects the time-range of
the free-busy request. If not ignore it.
2. For the time period covered by the "VAVAILABILITY" component,
mark time in the free-busy request result set as busy, using
the busy time type derived from the "BUSYTYPE" property in
the "VAVAILABILITY" component.
3. For each remaining "VAVAILABILITY" component:
1. For each "AVAILABLE" component in the "VAVAILABILITY"
component:
1. Expand all recurring instances, taking into account
overridden instances, ignoring those not within the free-
busy request time-range.
2. For each instance, mark the corresponding time in the
free-busy request result set as free.
4. For each "VEVENT" or "VFREEBUSY" component apply normal free-busy
processing within the free-busy request time-range.
4.1. Examples
In the examples below a table is used to represent time slots for the
period of a free-busy request. Each time slot is two hours long.
The column header represents the hours from midnight local time.
Each row below the column headers represents a step in the free-busy
result set determination, following the procedure outlined above.
Each cell in the rows below the column header contains a single
character that represents the free-busy type for the corresponding
time period at the end of the process step represented by the row.
The characters in the row are:
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+-----------+--------------------------------------------------+
| Character | Meaning |
+-----------+--------------------------------------------------+
| F | Represents "FREE" time in that slot. |
| B | Represents "BUSY" time in that slot. |
| U | Represents "BUSY-UNAVAILABLE" time in that slot. |
| T | Represents "BUSY-TENTATIVE" time in that slot. |
+-----------+--------------------------------------------------+
4.1.1. Simple Example
A free-busy request for Monday, 6th November 2006, midnight to
midnight in the America/Montreal timezone.
The user's calendar is as shown in Appendix A. This includes one
"VAVAILABILITY" component giving available time within the requested
time-range of 8:00 AM to 6:00 PM, together with one "VEVENT"
component representing a two hour meeting starting at 12:00 PM.
+------+----+----+----+----+----+----+----+----+----+----+----+----+
| Step | 0 | 2 | 4 | 6 | 8 | 10 | 12 | 14 | 16 | 18 | 20 | 22 |
+------+----+----+----+----+----+----+----+----+----+----+----+----+
| 1. | F | F | F | F | F | F | F | F | F | F | F | F |
| 2. | U | U | U | U | U | U | U | U | U | U | U | U |
| 3. | U | U | U | U | F | F | F | F | F | U | U | U |
| 4. | U | U | U | U | F | F | B | F | F | U | U | U |
+------+----+----+----+----+----+----+----+----+----+----+----+----+
More examples here../not sure what though.
5. CalDAV Extensions
5.1. CalDAV Requirements Overview
This section lists what functionality is required of a CalDAV server
which supports this extension. A server:
o MUST support "VAVAILABILITY" components in a calendar collection
resource if the CALDAV calendar-access feature is supported;
o MUST support CALDAV:free-busy-query REPORTs that aggregate the
information in any "VAVAILABILITY" components;
o MUST support "VAVAILABILITY" components stored in a CALDAV:inbox-
availability WebDAV property on a CALDAV scheduling inbox
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collection if the CALDAV calendar-auto-schedule feature is
supported;
o MUST support iTIP [I-D.ietf-calsify-2446bis] free busy requests
that aggregate the information in any "VAVAILABILITY" components
in calendar collections that contribute to free-busy, or in any
"VAVAILABILITY" components stored in the CALDAV:calendar-
availability in the CALDAV scheduling inbox collection of the
calendar user targeted by the iTIP free-busy request, if the
CalDAV calendar-auto-schedule feature is available.
5.2. New features in CalDAV
5.2.1. Calendar Availability Support
A server supporting the features described in this document MUST
include "calendar-availability" as a field in the DAV response header
from an OPTIONS request on any resource that supports any calendar
properties, reports, method, or privilege. A value of "calendar-
availability" in the DAV response header MUST indicate that the
server supports all MUST level requirements specified in this
document.
5.2.1.1. Example: Using OPTIONS for the Discovery of Calendar
Availability Support
>> Request <<
OPTIONS /home/bernard/calendars/ HTTP/1.1
Host: cal.example.com
>> Response <<
HTTP/1.1 200 OK
Allow: OPTIONS, GET, HEAD, POST, PUT, DELETE, TRACE, COPY, MOVE
Allow: PROPFIND, PROPPATCH, LOCK, UNLOCK, REPORT, ACL
DAV: 1, 2, 3, access-control, calendar-access,
calendar-availability
Date: Fri, 11 Nov 2005 09:32:12 GMT
Content-Length: 0
In this example, the OPTIONS method returns the value "calendar-
availability" in the DAV response header to indicate that the
collection "/home/bernard/calendars/" supports the new features
defined in this specification.
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5.2.2. CALDAV:free-busy-query REPORT
A CALDAV:free-busy-query REPORT can be executed on a calendar
collection that contains iCalendar "VAVAILABILITY" components. When
that is done, the server MUST aggregate the information in any
"VAVAILABILITY" components when generating the free-busy response, as
described in Section 4.
5.2.3. CALDAV:calendar-availability Property
Name: calendar-availability
Namespace: urn:ietf:params:xml:ns:caldav
Purpose: Defines a "VAVAILABILITY" component that will be used in
calculating free-busy time when an iTIP VFREEBUSY request is
targetted at the calendar user who owns the Inbox.
Conformance: This property MAY be protected and SHOULD NOT be
returned by a PROPFIND allprop request (as defined in Section
12.14.1 of [RFC2518]). Support for this property is REQUIRED.
The value of this property MUST be a valid iCalendar object
containing a single "VAVAILABILITY" component.
Description: This property allows a user to specify their
availability by including a VAVAILABILITY component in the value
of this property. If present, the server MUST use the
"VAVAILABILITY" component in the value of this property when
determining free-busy information as part of an iTIP VFREEBUSY
requested being handled by the server.
Definition:
<!ELEMENT calendar-availability (#PCDATA) >
; Data value MUST be iCalendar object containing a
; "VAVAILABILITY" component.
Example:
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<C:calendar-availability xmlns:D="DAV:"
xmlns:C="urn:ietf:params:xml:ns:caldav"
>BEGIN:VCALENDAR
CALSCALE:GREGORIAN
PRODID:-//example.com//iCalendar 2.0//EN
VERSION:2.0
BEGIN:VTIMEZONE
LAST-MODIFIED:20040110T032845Z
TZID:America/Montreal
BEGIN:DAYLIGHT
DTSTART:20000404T020000
RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4
TZNAME:EDT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20001026T020000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZNAME:EST
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTAMP:20061113T044111Z
DTSTART;TZID=America/Montreal:20061106T120000
DURATION:PT1H
SUMMARY:Meeting
UID:60A48841ECB90F3F215FE3D2@example.com
END:VEVENT
BEGIN:VAVAILABILITY
UID:20061005T133225Z-00001@example.com
DTSTAMP:20061005T133225Z
DTSTART;TZID=America/Montreal:20061002T000000
BEGIN:AVAILABLE
UID:20061005T133225Z-00001-A@example.com
SUMMARY:Monday to Friday from 9:00 to 18:00
DTSTART;TZID=America/Montreal:20061002T090000
DTEND;TZID=America/Montreal:20061002T180000
RRULE:FREQ=WEEKLY;BYDAY=MO,TU,WE,TH,FR
END:AVAILABLE
END:VAVAILABILITY
END:VCALENDAR
</C:calendar-availability>
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5.2.4. iTIP VFREEBUSY requests
The [I-D.desruisseaux-caldav-sched] processing of a "VFREEBUSY"
request targeted at the owner of the CALDAV:schedule-inbox will
include free-busy information derived from "VAVAILABILITY" components
in any calendar collection targeted during the request, as described
in Section 4. In addition, any "VAVAILABILITY" component specified
in the CALDAV:calendar-availability property on the owner's Inbox,
MUST be included in the free-busy calculation.
6. Security Considerations
Free-busy information generated from "VAVAILABILITY" components MUST
NOT include information other than busy or free time periods. In
particular, user specified property values such as "SUMMARY" and
"DESCRIPTION" MUST NOT be copied into the free-busy result data.
Beyond this, this specification does not add any additional security
issues that are not already present in [I-D.ietf-calsify-rfc2445bis]
and [I-D.ietf-calsify-2446bis].
7. IANA Considerations
7.1. Component Registrations
This documents defines the following new iCalendar components to be
added to the registry defined in Section 8.2.2 of
[I-D.ietf-calsify-rfc2445bis]:
+---------------+---------+----------------------+
| Component | Status | Reference |
+---------------+---------+----------------------+
| VAVAILABILITY | Current | RFCXXXX, Section 3.1 |
| AVAILABLE | Current | RFCXXXX, Section 3.1 |
+---------------+---------+----------------------+
7.2. Property Registrations
This documents defines the following new iCalendar properties to be
added to the registry defined in Section 8.2.3 of
[I-D.ietf-calsify-rfc2445bis]:
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+----------+---------+----------------------+
| Property | Status | Reference |
+----------+---------+----------------------+
| BUSYTYPE | Current | RFCXXXX, Section 3.2 |
+----------+---------+----------------------+
8. Acknowledgments
This specification came about via discussions at the Calendaring and
Scheduling Consortium.
9. Normative References
[I-D.desruisseaux-caldav-sched]
Daboo, C. and B. Desruisseaux, "CalDAV Scheduling
Extensions to WebDAV", draft-desruisseaux-caldav-sched-06
(work in progress), November 2008.
[I-D.ietf-calsify-2446bis]
Daboo, C., "iCalendar Transport-Independent
Interoperability Protocol (iTIP)",
draft-ietf-calsify-2446bis-08 (work in progress),
November 2008.
[I-D.ietf-calsify-rfc2445bis]
Desruisseaux, B., "Internet Calendaring and Scheduling
Core Object Specification (iCalendar)",
draft-ietf-calsify-rfc2445bis-09 (work in progress),
November 2008.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC2518] Goland, Y., Whitehead, E., Faizi, A., Carter, S., and D.
Jensen, "HTTP Extensions for Distributed Authoring --
WEBDAV", RFC 2518, February 1999.
[RFC4791] Daboo, C., Desruisseaux, B., and L. Dusseault,
"Calendaring Extensions to WebDAV (CalDAV)", RFC 4791,
March 2007.
Appendix A. Example Calendar #1
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Internet-Draft Calendar Availability November 2008
iCalendar object
BEGIN:VCALENDAR
CALSCALE:GREGORIAN
PRODID:-//example.com//iCalendar 2.0//EN
VERSION:2.0
BEGIN:VTIMEZONE
LAST-MODIFIED:20040110T032845Z
TZID:America/Montreal
BEGIN:DAYLIGHT
DTSTART:20000404T020000
RRULE:FREQ=YEARLY;BYDAY=1SU;BYMONTH=4
TZNAME:EDT
TZOFFSETFROM:-0500
TZOFFSETTO:-0400
END:DAYLIGHT
BEGIN:STANDARD
DTSTART:20001026T020000
RRULE:FREQ=YEARLY;BYDAY=-1SU;BYMONTH=10
TZNAME:EST
TZOFFSETFROM:-0400
TZOFFSETTO:-0500
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
DTSTAMP:20061113T044111Z
DTSTART;TZID=America/Montreal:20061106T120000
DURATION:PT1H
SUMMARY:Meeting
UID:60A48841ECB90F3F215FE3D2@example.com
END:VEVENT
BEGIN:VAVAILABILITY
UID:20061005T133225Z-00001@example.com
DTSTAMP:20061005T133225Z
DTSTART;TZID=America/Montreal:20061002T000000
BEGIN:AVAILABLE
UID:20061005T133225Z-00001-A@example.com
SUMMARY:Monday to Friday from 9:00 to 18:00
DTSTART;TZID=America/Montreal:20061002T090000
DTEND;TZID=America/Montreal:20061002T180000
RRULE:FREQ=WEEKLY;BYDAY=MO,TU,WE,TH,FR
END:AVAILABLE
END:VAVAILABILITY
END:VCALENDAR
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Appendix B. Change History (To be removed by RFC Editor before
publication)
Changes from -00:
1. Allow property on Inbox for caldav-schedule.
2. Clarify that DURATION can only be present in VAVAILABILITY if
DTSTART is also present, and DTEND is not.
3. Updated references.
4. Added templates.
Authors' Addresses
Cyrus Daboo
Apple Inc.
1 Infinite Loop
Cupertino, CA 95014
USA
Email: cyrus@daboo.name
URI: http://www.apple.com/
Bernard Desruisseaux
Oracle Corporation
600 blvd. de Maisonneuve West
Suite 1900
Montreal, QC H3A 3J2
CA
Email: bernard.desruisseaux@oracle.com
URI: http://www.oracle.com/
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Full Copyright Statement
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Daboo & Desruisseaux Expires May 7, 2009 [Page 19]
