Willy-Bas Loos <willybas@gmail.com> writes:
> Is there a reason for this change of behavior between 8.4 and 9.* ?
See the "incompatibilities" section in the 9.2 release notes:
* Make EXTRACT(EPOCH FROM timestamp without time zone) measure the
epoch from local midnight, not UTC midnight (Tom Lane)
This change reverts an ill-considered change made in release
7.3. Measuring from UTC midnight was inconsistent because it made
the result dependent on the timezone setting, which computations
for timestamp without time zone should not be. The previous
behavior remains available by casting the input value to timestamp
with time zone.
regards, tom lane