SYS_EXTRACT_UTC
extracts the UTC (Coordinated Universal Time—formerly Greenwich Mean Time) from a datetime value with time zone offset or time zone region name. If a time zone is not specified, then the datetime is associated with the session time zone.
The following example extracts the UTC from a specified datetime:
SELECT SYS_EXTRACT_UTC(TIMESTAMP '2000-03-28 11:30:00.00 -08:00') FROM DUAL; SYS_EXTRACT_UTC(TIMESTAMP'2000-03-2811:30:00.00-08:00') ----------------------------------------------------------------- 28-MAR-00 07.30.00 PM