Re: Date/Time Types : internals - Mailing list pgsql-docs

From Tom Lane
Subject Re: Date/Time Types : internals
Date
Msg-id 9773.1334780084@sss.pgh.pa.us
Whole thread Raw
In response to Re: Date/Time Types : internals  ("Kevin Grittner" <Kevin.Grittner@wicourts.gov>)
Responses Re: Date/Time Types : internals  (Florence Cousin <cousinflo@free.fr>)
Re: Date/Time Types : internals  (Robert Haas <robertmhaas@gmail.com>)
List pgsql-docs
"Kevin Grittner" <Kevin.Grittner@wicourts.gov> writes:
> I guess the point is that for hundreds of years, the same day could
> have a different date depending which country's calendar you were
> looking at.  I'm not entirely clear why there's a problem if you
> pick the Gregorian calendar and apply it retroactively.

Which is, in fact, exactly what our code does.  I think that bit in the
docs is trying to explain why we do that rather than try to get the
code to reflect what people really used back then.

A possibly comparable point is that for timezone info we use the Olsen
database (tzdata), which *does* make an effort to reflect historical
realities.  In consequence, at least once every several months we
get somebody complaining about what a strange GMT offset he's seeing
for timestamps before 1900 or so.  If there's anyone out there who
actually likes that behavior, we've not heard about it.  (Not that
I am going to try to get Olsen et al to change their policy.)

            regards, tom lane

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