[Cosmo-dev] Warning about US and Canada divergence

[Jeffrey Harris]

Hi Folks

The conversation about timezones has reminded me that we should probably
 warn users, when they're choosing a timezone, that US and Canadian
timezones are subtly different now.  If we guess automatically, in many
cases we're likely to guess wrong.  See below:

Jeremy Epstein wrote:
> With a couple of heuristics in place, I believe its possible to make
> the right choice 90% of the time.  Not only that but if there are 24
> choices in the list its a long one to navigate. I am also  assuming
> that you will not force users to distinguish between PST and PDT-- as
> a point of convention that should be done auto-magically-- i.e. a
> user chooses "pacific time" or some such thing and the correct
> time(daylight savings or not)  is calculated.

Actually, I think many users machines will have out of date timezone
databases.  So if we're going to use accurate heuristics (accurate
defined as matching an up to date database), many, if not most, US users
timezones will inaccurately be interpreted as being Canadian timezones,
since the Canadian DST shifts are now what US timezones used to be.

Sincerely,
Jeffrey