Using v6.4 I see the following 30-year minus 1-day error:
hist=> select date_part('epoch','11/7/1998'::datetime)::date;
date
----------
11-06-2028
(1 row)
hist=> select date_part('epoch','11/7/1998'::date)::date;
date
----------
11-06-2028
(1 row)
mike
--
Dr Michael A. Koerber
MIT/LL
Radar Imaging Techniques