Subject: [VCARDDAV] Non-Gregorian Calscales?

From: DataPacRat <[email-masked]>
Date: Fri, 13 Sep 2013 01:09:43 -0400

I've been digging around a bit; and I can't seem to find any registry,
list, RFC, or other IETF or IANA mention of values for vCard's
"CALSCALE" other than 'Gregorian'.

RFC6350 mentions the possibility in section 5.8, and refers to RFC5545
section 3.7.1, which only says, "It is expected that other calendar
scales will be defined in other specifications or by future versions
of this memo."

Creating a hodgepodge of RFCs for various calendar systems seems like
a less-than-optimal way to go about things. If there currently is no
IANA registry of calendar systems, the way there is of language
subtags, it feels like there should be one. Assuming that my Google-fu
is strong enough that I haven't simply missed finding an existing
registry... who should I get in touch with to discuss the pros and
cons of starting one, and if the former outweigh the latter, the best
ways to go about it?

Thank you for your time,
--
DataPacRat
"Then again, I could be wrong."

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From: Filip Navara <[email-masked]>
Date: Fri, 13 Sep 2013 09:16:22 +0200

http://tools.ietf.org/html/draft-daboo-icalendar-rscale-01 refers to
Unicode BCP47 for possible values and there's pretty good rationale for
using that.

http://unicode.org/repos/cldr/trunk/common/bcp47/calendar.xml

Best regards,
Filip Navara

On Fri, Sep 13, 2013 at 7:09 AM, DataPacRat <[email-masked]> wrote:

> _______________________________________________
> VCARDDAV mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/vcarddav
>

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From: Cyrus Daboo <[email-masked]>
Date: Fri, 13 Sep 2013 09:53:43 -0400

Hi Filip,

> http://unicode.org/repos/cldr/trunk/common/bcp47/calendar.xml

Yes that is correct. However, note that the rscale draft does not address 
the issue of any changes to the actual date format itself, since it only 
describes how recurrence rule patterns can be applied in a different 
calscale (the actual date/time represzentation in iCalendar remains as 
Gregorian).

A proper implementation of non-Gregorian date/time values will need to 
re-define what the format of the date value is. I don't believe ISO-8601 
covers all the possibilities (for example Japanese calendars require an 
"era" element).

-- 
Cyrus Daboo

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From: DataPacRat <[email-masked]>
Date: Sat, 14 Sep 2013 04:14:31 -0400

> covers all the possibilities (for example Japanese calendars require an

Expanding all of vCard to properly handle non-Gregorian dates will
probably have to wait until version 4.1. I'm currently concerned about
the DATE parameter I'm adding in the Signed vCards draft. Given that
the formal format of standard vCard date-and-or-time formats are
nearly inextricably linked to Gregorian dates, I'm probably going to
end up throwing in a statement along the lines of, "This format
assumes the default, Gregorian CALSCALE, which ISO 8601 is based on.
Non-Gregorian CALSCALEs should use the format most appropriate to that
calendar." Does that sound like an acceptable placeholder, until such
time as vCard is revamped?

Thank you for your time,