Before I open a bug on this, I wanted to do a sanity check, since there may be something I'm just not seeing. I'm using PostgreSQL 8.2.3 and seeing this behaviour with timezones: select create_date from article_lead; create_date --------------------------- 2007-11-04 16:35:33.17+00 2007-11-04 04:35:36.09+00 2007-11-05 04:35:36.38+00 2007-11-05 16:35:36.67+00 (4 rows) select create_date from article_lead where create_date >= '2007-11-03 17:00:00.0' and create_date <='2007-11-04 16:00:00.0'; create_date --------------------------- 2007-11-04 04:35:36.09+00 Shouldn't that second row have been in the results of the second query? (create_date is of timestamptz type). Also noted this oddity, though it may be unrelated: set TimeZone='America/Los_Angeles'; select create_date from article_lead; create_date --------------------------- 2007-11-04 08:35:33.17-08 2007-11-03 21:35:36.09-07 <-- why 07? 2007-11-04 20:35:36.38-08 2007-11-05 08:35:36.67-08 Nick ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend