Você deve ser capaz de usar o
AT TIME ZONE sintaxe SELECT column_name at time zone 'UTC'
FROM your_table
ou seja
SQL> select * from foo;
COL1
---------------------------------------------------------------------------
09-FEB-12 01.48.40.072000 PM -05:00
09-FEB-12 10.49.26.613000 AM US/PACIFIC
SQL> select col1 at time zone 'UTC'
2 from foo;
COL1ATTIMEZONE'UTC'
---------------------------------------------------------------------------
09-FEB-12 06.48.40.072000 PM UTC
09-FEB-12 06.49.26.613000 PM UTC
