Timezone translations

Ken Pizzini tz. at explicate.org
Sun Jun 5 08:20:08 UTC 2005

On Sat, Jun 04, 2005 at 04:04:46PM -0700, Mark Davis wrote:
> Here is the problem. You fill in a calendar form for a recurring meeting,
> one that is to happen at "10:00 am GMT". If (a) the software maps the "GMT"
> to the tzid Europe/London, then the time of that meeting will be 10:00Z in
> the winter, and change to 09:00Z in the summer. If (b) the software maps
> "GMT" to Etc/GMT, then that meeting will be at 10:00Z all year round. It
> can't do both, and doing (a) would cause all kinds of other problems.
> If you (or others) have any ideas for handling this, I'd be glad to forward
> them.

For this specific case, the right thing to do is discourage the old
historical (pre-1972) usage of GMT as "universal time", and promote
the proper modern term UTC instead.  Said a different way, GMT is
the time that Britan observes during the winter; UTC is the so-called
"universal" time that most countries use as a reference for their
civil time (adjusted by the local zone offset); use of GMT to mean
UTC is wrong (though apparently still quite common).

		--Ken Pizzini

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