[tz] Turkey to delay DST

John Hawkinson jhawk at mit.edu
Thu Feb 27 23:38:59 UTC 2014

Andy Heninger <aheninger at google.com> wrote on Thu, 27 Feb 2014
at 15:32:42 -0800 in <CAFXfk_3HsxkRK1UmEj0_rb5uVN-E-6QWN7HbQcqUUv25t7iEfg at mail.gmail.com>:

> When users schedule events, the times are typically stored in a calendar
> database in UTC/GMT.

This is, of course, the wrong way to go.
What *SHOULD* happen is that events should have a home timezone, and
they should be stored in that timezone. It may be a different home timezone
for different events, and some software may not be so flexible, but that's
how it should work.

Defaulting to UTC is just wrong -- it'll be more wrong than it is right,
and is worse than just using the user's local timezone (and remembering
what it is).

> 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.

For events shared among multiple people it's not great, but the
answer is to pick a timezone for the event, typically the timezone of
the lead host, and reference it clearly.

--jhawk at mit.edu
  John Hawkinson

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