Vadim Nasardinov <vadimn@redhat.com> writes:
> Based upon a very cursory reading of the documentation, it seems to be
> that PostgreSQL uses a hardcoded internal list of time zones for
> dealing with timezone *input*, but it uses the underlying OS's
> facilities for dealing with timezone *output*. But then again, the
> docs seems to have changed between 7.4 and 8.0.
That's because the underlying implementation was completely revamped.
We now have our own timezone code and timezone database (the latter
being the zic database) to avoid depending on the OS facilities.
regards, tom lane