In this example, the TruncRoundReturnTimestamp DBS Control field is set to TRUE; therefore, ROUND returns a TIMESTAMP value when the input data type is TIMESTAMP.
SELECT ROUND( cast('2003-08-17 12:15:23+05:00' as timestamp with time zone),'HH24');
Result:
ROUND('2003-08-17 12:15:23+05:00','HH24') ----------------------------------------- 2003-08-17 12:00:00.000000+05:00