[tz] Converting cities to tz identifiers (tangent)

Brian Inglis Brian.Inglis at SystematicSw.ab.ca
Mon Feb 26 05:56:24 UTC 2018

On 2018-02-21 03:27, Adam Vartanian via tz wrote:
>>> What is meant by "the US Eastern time zone"?
>> I think the colloquial meaning applies. The case I'm thinking of would be 
>> things like a hotline which advertises its hours in "Eastern time" rather
>> than the time zone of a specific city, or a distributed team following
>> roughly US time zone rules that schedules their meetings in "Eastern time"
>> even though the members of the team are in various locations.
> Fortunately, every US location in the Eastern time zone observes DST, so the 
> city doesn't currently matter.
> But what happens if somebody decides to schedule a meeting in "Mountain time"
> some time between 2 o’clock antemeridian on the second Sunday of March and 2
> o’clock antemeridian on the first Sunday of November?  That wouldn't suffice;
> you'd either have to explicitly schedule it for "Mountain standard time" or
> "Mountain daylight time", or treat it as implied that Arizona doesn't count
> and "Mountain time" is "Mountain daylight time" during that period.
> In my experience, usage in everyday speech is generally that Arizona is said to
> spend the winters in Mountain time and the summers in Pacific time, rather than
> spending the whole year in Mountain standard time.  So if you say "Mountain
> time" in the summer, people understand that to be UTC-6, even when dealing with
> people in Arizona.
> This is kind of fuzzy definition is insufficient for a project like tzdb, but in
> a user interface it might well be the best understood option.

Indeed I am sure that, as in Saskatchewan, Canada, which stays on CST year
round, while local time stamps are probably marked CST, national schedules are
as if on MDT, and in Arizona, USA, on PDT, as GMT-n is not a common notation.

Take care. Thanks, Brian Inglis, Calgary, Alberta, Canada

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