[tz] Turkey to delay DST

John Haxby john.haxby at oracle.com
Fri Feb 28 09:38:05 UTC 2014

On 27/02/14 23:32, Andy Heninger wrote:
> When users schedule events, the times are typically stored in a calendar
> database in UTC/GMT. The conversion happens when the event is created.
> If a subsequent tz rule update changes the GMT offset of the (future)
> event times, the previously scheduled events will appear to move. For
> events that are shared among people in multiple time zones there is no
> good answer.

That doesn't work.

I'm in the UK, but I have a weekly meeting scheduled for 11am pacific
time.  It's always at 11am in California, week in, week out.  When the
US switches to and from DST it's still at 11am local time.  For me, in
the UK, it's at 7pm most of the year but for two weeks in Spring it's at
6pm and for a week in Autumn it's also at 6pm.

If it were a constant time in UTC then the weekly meeting would be at a
different local time for the whole of the summer months, both in the UK
and in California.

The rule really is "Each Monday at 11am, America/Los_Angeles time".  And
even should legislation change the definition of America/Los_Angeles,
that would still be the case.  (Legislation can't change past timezones,
not without a time machine.)


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