OT : timestamps and jbuilder (help, please)

hi everybody, hope any one can give me some insigth about this one, we
are in great despair :(

we are developing an application using jbuilder 5 and postgresql
7.2.2-1PGDG, and found some strange beheavior with the timestamps, say
for example, in our database we have a record like this one:

id_emp | name | date
--------+--------+------------------------
1004 | laura | 2002-09-19 00:00:00-05

but when displaying this same date in a textfield in our application, it
says the date is 2002-09-18 23:00:00!!!!

the date field is a timestamp with time zone, we tried using a timestamp
without time zone, but our app starts complaining when trying to save
changes to the database about not finding the original row

it gets worst as we need the right date to make some calculations about
the number of days between dates.

when querying this same database using SquirrelSQL (a java database
client), the date apperas correctly as is in the database, so i think
the problem is with the borland dataexpress components, but i'm not
sure, so if somebody got the same problems, it would be greatly
appreciated if can share the solution

many thanks in advance, and best regards