[Design][Decision] Floating timezones

[Jeffrey Harris]

Hi Mimi,

> + Add a preference to "turn on" timezone support

OK, lets try it.

> + Prior to turning on timezone support, all events are stored as
> "floating". As a result, if you change the timezone on your computer,
> none of your events will shift.

+1, that makes sense.

> + Once you've turned on timezone support, all events are stored in
> "local time" (whatever timezone your computer is set to) and then
> timezones proceed to work the way they do today.

Does this imply that flipping the preference means we should go through
the repository and convert existing floating dates to the local
timezone?  Or just that timezone UI is enabled and new events are given
a timezone by default?

-1 to the former, +1 to the latter.  Basically, I'd prefer that turning
time zones on and off affected UI, not how items are stored in the
repository.

If we want the behavior of assigning floating times to the current
timezone, perhaps we could add a button to do that in the (currently
non-existent, admittedly) preferences?

> + Nice to have: You turn on timezone support, you make a bunch of
> timezone adjustments. Then you turn off timezone support. We somehow
> remember your timezone adjustments if you turn on timezone support again.

Assuming the timezone preference has no impact on items already in the
repository, this is easy.  If not, hmm.

> + If you have timezone support turned off and receive, import or
> subscribe to event(s) that have timezone information, the following
> could happen:
> ++ A dialog pops up telling you that you either have to turn on timezone
> support or lose timezone info on the data you're adding to your calendar.
> ++ The events display in the calendar in "floating time", but in the
> detail view, you can see what timezone they're in.

I like the latter best.

Sincerely,
Jeffrey