Re: BUG #3948: date/time functions returning wrong value

Alvaro Herrera <alvherre(at)commandprompt(dot)com> writes:
> I think what I conclude from this is that Windows TZ database is so
> bogus that we should avoid trying to rely on it -- I say if the user
> does not set "timezone" in postgresql.conf, refuse to start.

Remember we're also relying on the OS for the time of day :-(.
I'm not sure there's any point in trying to be a lot better than
it is about timekeeping. In particular, even if the user has set
the displayed local time correctly, what Windows will tell us the
UTC time is depends entirely on its idea of the timezone offset.
If we have a different idea of the timezone offset, all it will buy
us is complaints from users that our time is wrong.

(Now, this pessimistic view of things might be obsolete if Windows
systems commonly get their UTC time from NTP, as is standard on
Linux and Mac these days. I hadn't heard that Microsoft was up
to speed on that, though --- if they did, I think it'd force them
to be a whole lot more careful keeping their local timezone knowledge
up to date ...)

regards, tom lane