[Ietf-calsify] Re: What's wrong with more radical simplification?
helge.hess at opengroupware.org
Fri Feb 11 12:28:50 PST 2005
On 11. Feb 2005, at 21:12 Uhr, Michiel van Leeuwen wrote:
> Let's assume that timezones move to an extension. The client i use
> supports them. So, the start time of en event is defined with a
No, the start time would still be defined in UTC, the timezone would be
added as a hint (actually a required one for the rrules extension).
> I publish the calendar. (upload the whole ics file). Someone else
> reads it using a client that doesn't support timezones. How can he
> fall back?
See above, the times will always be in UTC, the timezone is additional
information. So its a non-issue.
> he has to ignore the timezone information, because he doesn't
> understand it.
Yes, and it won't hurt since the time value is always in UTC, there is
no reason to do it otherwise. We only transport timezone information to
a) add information for editors/viewers
b) to allow for rrules
You seem to miss the reasons when and why timezones are required in the
protocol/format? I'm somewhat surprised about that, since exactly this
was discussed only some weeks ago including some details on how this
could be done format-wise.
> He can either use the time in the wrong timezone, or ignore the time
> completely. Both is wrong.
Yes, because your assumptions is wrong. To be up/downwards compatible
timevalues would always be in UTC.
> So, if i want my calendar to be readable by other clients, i can't use
> The same story would hold for other extensions.
Of course extensions must be properly done to be compatible, but so far
both discussed items can be easily done as extensions while still
providing downwards compatibility AND provide the same functionality
BTW: we do not talk about timezone awareness in the client, this has to
be available in any case. This is only about including timezone
information in the protocol entity which is only required for
recurrences and to one kind of allday appointments (as far as I can
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