FROM_TZ converts a timestamp value and a time zone to a TIMESTAMP WITH TIME ZONE data type.
TIMESTAMP WITH TIME ZONE
FROM_TZ (timestamp_value, time_zone_value)
timestamp_value is an expression with a TIMESTAMP data type.
time_zone_value is a text expression that returns a string in the format TZH:TZM or in TZR with optional TZD format.
FROM_TZ(TIMESTAMP '2008-03-26 08:00:00', '3:00') returns the value 26-MAR-08 08.00.00.000000 AM +03:00.