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Calendaring Extensions
charter-ietf-calext-00-04

The information below is for an older proposed charter
Document Proposed charter Calendaring Extensions WG (calext) Snapshot
Title Calendaring Extensions
Last updated 2014-08-28
State IESG Review (Charter for Approval, Selected by Secretariat) Rechartering
WG State Proposed
IESG Responsible AD Orie Steele
Charter edit AD Barry Leiba
Send notices to cyrus@daboo.name, calsify@ietf.org

charter-ietf-calext-00-04

The Calendaring Extensions working group is chartered to develop
extensions to the iCalendar (RFC 5545), iTIP (RFC 5546), and
CalDAV (RFC 4791) standards.

This working group will do the following:

  • Develop an extension to iCalendar to support non-Gregorian recurrence
    rules, without the need to support new calendar scale values in
    iCalendar as a whole. This will allow for easy implementation of the
    primary use case for non-Gregorian support in calendar systems, without
    the need for significant changes to the iCalendar format. The
    non-Gregorian calendar system should be based on the International
    Components for Unicode work by the Unicode Consortium
    (http://site.icu-project.org).

  • Develop an extension to iCalendar to support a new component type that
    allows users to express arbitrary, possibly repeating, periods of
    "available" time. The primary use case for this is for users to express
    their "office hours" (e.g., Monday-Friday, 9am-5pm) in a standard way to
    ensure free busy lookups show the correct periods of availability.

  • Define a set of new iCalendar properties and parameters to standardise
    some existing experimental X- properties in common use, based on a
    survey of existing implementations.

  • Define a set of new iCalendar properties and parameters to cover key
    uses cases that implementers have identified, including, but not
    limited to, a new "IMAGE" property (to allow embedding/linking of
    images tied to a specific event), and a "CONFERENCE" property (to allow
    embedding information about dial-in numbers and similar multi-party
    communication options for an event).

The working group will work under the following parameters:

  • The extensions developed are expected to be backwards-compatible with
    the existing calendar standards. Incompatibilities must be identified,
    minimized, and justified.

  • For each set of extensions, examine their impact on the iTIP protocol
    (RFC 5546), and define any necessary extensions to iTIP to accommodate
    such impact.

  • For each set of extensions, examine their impact on the CalDAV
    protocol (RFC 4791), and define any necessary extensions to CalDAV to
    accommodate such impact. Interface with the httpbis working group to
    ensure that any CalDAV changes are consistent with good http practices.

The working group will use the following drafts as initial input for its
work:
draft-daboo-icalendar-rscale-03
draft-daboo-calendar-availability-05
draft-daboo-icalendar-extensions-08

The following are out of scope for the working group:

  • Any change that impacts backwards compatibility with existing
    deployed iCalendar/iTIP/CalDAV clients and servers will be discussed
    by the working group with a view to minimizing disruption to deployed
    implementations without compromising desirable new function.

  • Any attempt to develop non-Gregorian calendar systems/calculations.