Time zone suggestions for draft-ietf-calsch-ical-08.txt

Paul Eggert eggert at twinsun.com
Mon Aug 10 22:03:14 UTC 1998

   Date: Mon, 10 Aug 1998 11:28:21 +0200
   From: Antoine Leca <Antoine.Leca at renault.fr>

   the naming scheme for timezones should be extensible.  Right, Paul?

Yes.  The number of time regions will increase with time.

   > Besides, iCalendar should work for dates before 1998; I'd want to use
   > it that way myself.  Why limit it to future dates?

   the aim here is to do a world-wide repository about timezones
   suitable for Internet scheduling, and here I believe the past
   problems will be an additional weight with no useful properties.

It might be reasonable for iCalendar to ignore transitions before,
say, July 1998 when considering what regions to have in its world-wide
repository.  This would lower the number of regions considerably.

But why bother?  The existing tz data gets you back to 1970 for free.
It should be slightly more work to start with July 1998 (because
you'll have to coalesce regions, select canonical representatives, and
so forth) than to start with January 1970 (which should be a simple
data translation).

   Date: Mon, 10 Aug 1998 11:56:18 +0200
   From: Antoine Leca <Antoine.Leca at renault.fr>

   "Europe/London" and "Europe/Lisbon", that have very
   different history as timezones, but that are now equal, and also
   equal in the foreseable future.

That's not a good example, as Europe/London and Europe/Lisbon are
currently distinct.  Their TZNAMEs differ: Europe/London uses
`GMT/BST', whereas Europe/Lisbon uses `WET/WEST'.  (Also, when the
liberals return to power in Portugal, they may well switch the clocks
forward again.  :-)

However, I agree with your main point: the number of regions will
decrease if we drop Europe/Berlin, Europe/Rome, etc. and standardize
on Europe/Paris.

Would this be acceptable politically, though?  As Keith Moore pointed
out, J. Random Windows user in, say, Berlin might be a bit upset if he
has to point his browser at Paris to set his time zone.

   I believe that we should try to keep a minimum number of timezones,
   at least to not have to worry small implementations, and
   to keep the requirements on network traffic as small as possible.

Can you estimate how much would be saved by going with a 1998 horizon
versus a 1970 horizon?  I don't think it would be all that much, but I
don't know what the assumptions are.

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