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Re: doodle (Re: Scheduling calendaring coordination call.)

From: Robin Berjon <robin@robineko.com>
Date: Tue, 7 Sep 2010 15:35:15 +0100
Cc: Rich Tibbett <rich.tibbett@gmail.com>, Thomas Roessler <tlr@w3.org>, W3C Device APIs and Policy WG <public-device-apis@w3.org>
Message-Id: <548B072A-5A7F-4F97-8CAF-2DABA507D484@robineko.com>
To: Cyrus Daboo <cyrus@daboo.name>
On Sep 7, 2010, at 15:05 , Cyrus Daboo wrote:
> So having thought about this a little, the following would be needed in iCalendar to support alternative calendar systems:
> 1) A generalization of the ISO-8601 date-time format subset, as used by iCalendar, to support other calendar scales. At its simplest this probably means relaxing the limits on the month and day values (i.e., some calendar systems have more than 12 months in a year).
> 2) Change the RRULE property definition to support arbitrary calendar systems. e.g., right now the RRULE property defines some elements that use Gregorian day name abbreviations (SU, MO, TU, WE, TH, FR, SA). So those should be changed to perhaps a numeric or alpha representation with a well-defined mapping to actual day names in each calendar system. With that the current RRULE definition may also be sufficient for use with other calendar systems.
> Again this all boils down to the question of whether recurrence rules are a requirement for non-Gregorian systems. I think that is the first question that must be answered.

I believe that they are  the use cases I've heard seem to frequently involve birthdays and holidays.

But there's also a pragmatic sausage-factory aspect to take into consideration. It seems that properly supporting recurrence in non-Gregorian calendars would require non-trivial changes to iCalendar. We're happy to help, but we're the wrong group to do that. I think this is pointing at an update to iCalendar, which we would mirror in a future revision.

I'd like to find a solution that is as I18N-friendly as possible but can be made to work atop iCalendar as deployed today. I'm not at all fluent with calendar modelling, but could we recommend that:

   in version 1, for non-Gregorian calendars, a long list of RDATE be generated; and
   an X-USER-CALENDAR extension (which we'd define) be included to specify which calendaring system to use when displaying the event?

Robin Berjon
  robineko  hired gun, higher standards
Received on Tuesday, 7 September 2010 14:36:03 UTC

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