Time Zone Localizations

John Cowan cowan at ccil.org
Mon Jun 14 01:30:31 UTC 2004

Mark Davis scripsit:

> 3. What is the meaning of an TZID

Just what is the meaning of "meaning" in this context?

> 4. What is the versioning scheme, including assurance that:
>     - once a version is issued it is never changed.
>     - TZIDs are stable, in the sense that they will never be withdrawn
>       or reused with a substantially different semantic in later versions

Again, what does that mean?  New York might move to a new timezone,
if Congress so decided, or if it became an independent country (hey,
we pay them more than they pay us).  In that case the Eastern zone would
have to be renamed America/Philadelphia, or whatever.

More probably, Congress might change the DST rules, in which case the
current predictions of the U.S. zones would become incorrect and would
have to be updated.

The only other conceivable scenario would be for the Big Apple to have
its name changed (Nueva York might be a possibility).  In that case, some
other New York might come to prominence such that it became the largest
city in some other time zone in the Americas.  That's not very likely,
but it would constitute a genuine reuse.

The advantage and disadvantage of Olson TZIDs is that they aren't
arbitrary: they depend entirely on facts on the ground.

John Cowan   jcowan at reutershealth.com   http://www.reutershealth.com
    "Mr. Lane, if you ever wish anything that I can do, all you will have
        to do will be to send me a telegram asking and it will be done."
    "Mr. Hearst, if you ever get a telegram from me asking you to do
        anything, you can put the telegram down as a forgery."

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