[tz] Converting cities to tz identifiers (tangent)

Steve Allen sla at ucolick.org
Wed Feb 21 00:12:29 UTC 2018

On Tue 2018-02-20T15:41:05-0800 Paul Eggert hath writ:
> As Guy Harris wrote, the whole idea of TZ='US/Eastern' is
> reasonably fuzzy and there's certainly no expectation of a
> particular time zone history for it.

I think a US lawyer would disagree that there is any fuzziness for the
"time zone" US/Eastern *if* that were defined as in 15USC260 thru
15USC263.  The Uniform Time Act of 1966
was passed 1966-04-13 and specified that all local times in the US
were to be set forward on last Sunday April and back on last Sunday
October.  That was in effect at the tz cutoff of 1970-01-01 and though
the spring/fall dates have subsequently changed there is never any
ambiguity about the meaning in the US.

The fuzziness arises because US/Eastern is a "tz region" as defined by
tzdb, not a "time zone" as defined by US law.

Steve Allen                    <sla at ucolick.org>              WGS-84 (GPS)
UCO/Lick Observatory--ISB 260  Natural Sciences II, Room 165  Lat  +36.99855
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