In this example, the result of the CAST is the timestamp formed from the source expression value '2008-05-14' and the default time '00:00:00' adjusted to UTC by the current session time zone displacement, INTERVAL '06:00' HOUR TO MINUTE. Thus, the value of the CAST is '2008-05-13 18:00:00' at UTC with the current session time zone displacement INTERVAL '06:00' HOUR TO MINUTE.
The result value of the CAST at UTC is adjusted to its time zone displacement, INTERVAL '06:00' HOUR TO MINUTE, so the result of the SELECT statements is: TIMESTAMP '2008-05-14 00:00:00+06:00'.
SET TIME ZONE INTERVAL '06:00' HOUR TO MINUTE; SELECT CAST(DATE '2008-05-14' AS TIMESTAMP(0) WITH TIME ZONE); SELECT CAST(DATE '2008-05-14' AS TIMESTAMP(0) WITH TIME ZONE AT LOCAL);