Re: [VCARDDAV] New Date Range Proposal

[Cyrus Daboo <[e-mail]>]

Hi Markus,

--On October 14, 2010 9:34:39 AM +0200 Markus Lorenz 
<[e-mail]> wrote:

> What about a formal description like:
>
>    date-range = date-and-or-time "/" date-and-or-time
>
>    date-range-list = date-range *("," date-range)
>
> I'm not sure if "date-and-or-time" is the best solution, as it would
> allow values with only time and no date. But at the moment I couldn't
> think of a reason not to allow that. It shouldn't be the problem of the
> vCard format whether or not a given date-range is meaningful.
>
> With "date-range-list" we're quite near to being able to define business
> hours for work phone numbers. We'd only have to introduce weekdays.
> Don't know if anyone would like that. I guess this information could
> already be included in the iCalendar to which FBURL points. At least for
> the whole vCard and not a specific communications property.

Well that is a slippery slope because if you want to refer to recurring 
times then you need to take timezones (Daylight Saving Time rules) into 
account. I really don't think we should go there. If we do stick with a 
full date-time option here then we need to be clear about the timezone - 
either we pick UTC always, or allow a TZID parameter to be encoded somehow, 
but that would be awkward given that this item is itself a parameter.

What I would prefer is to drop the time component altogether and just go 
with dates only - I think that covers the majority of use cases and is 
sufficient level of granularity. If you want to specify something like work 
hours etc then that should be done by a pointer to an iCalendar object (or 
we define a way to embed an iCalendar object directly in the vCard - which 
is interesting because we also want to have iCalendar objects that 
reference vCards).

-- 
Cyrus Daboo