Re: [VCARDDAV] Non-gregorian dates

[Cyrus Daboo <[e-mail]>]

Hi Mike,

--On January 17, 2010 3:35:18 PM -0500 Mike Douglass <[e-mail]> wrote:

> Would it be appropriate to allow for multiply occurring properties in
> this case, for example allowing a birthday to appear in GREGORIAN and
> some other calscale - or is that essentially already covered?
>
> It seems likely (an open invitation for correction) that an application
> generating vcard that understands a non gregorian scale would also be
> able to produce gregorian equivalents.
>
> Given the note it's apparent that producers and consumers would need to
> refresh their information periodically - but then we have CardDAV for
> that.

An exact date can easily be mapped between different calendar systems using 
well known algorithms. What can't be done easily is partial dates - in some 
ways this is similar to recurrence patterns in iCalendar which are also 
very calscale specific. In this case consider my "partial" birthday:

BDAY:??0921

That won't necessarily map to the same date in other calendar systems for 
different years. e.g. (using <http://www.hebcal.com/converter/>). For 2010 
the Hebrew date is "13th of Tishrei, 5771", for 2011 it is "22nd of Elul, 
5771". Now I honestly don't know how one would represent something like a 
birthday in the Hebrew calendar or others (something I would like to 
research if I did not have plenty of other things to do) but I know users 
do want to be able to do that.

-- 
Cyrus Daboo