On Sat 2021-05-22T16:56:53-0400 Tom Lane via tz hath writ:
The reason I suggest this is that we regularly get questions on the Postgres lists from novices who are confused by this behavior (pardon the SQL-isms):
postgres=# set timezone = 'UTC'; SET postgres=# select timestamptz '1884-01-01 12:00 America/New_York'; timestamptz ------------------------ 1884-01-01 17:00:00+00 (1 row)
This is, of course, saying that noon in New York translates to 1700 UT ...
postgres=# select timestamptz '1883-01-01 12:00 America/New_York'; timestamptz ------------------------ 1883-01-01 16:56:02+00 (1 row)
... uh, what? The novices are definitely not expecting that,
and they don't find it helpful. We have to explain it away as "that's what tzdb says", but it's still unhelpful.
It serves to remind folks that there is a point in time before which the question they think they asked has no meaning; that if they want precise time before then they will have to decide what question they are trying to answer. -- Steve Allen <sla@ucolick.org> WGS-84 (GPS) UCO/Lick Observatory--ISB 260 Natural Sciences II, Room 165 Lat +36.99855 1156 High Street Voice: +1 831 459 3046 Lng -122.06015 Santa Cruz, CA 95064 https://www.ucolick.org/~sla/ Hgt +250 m