Dateadd was added in DBR 10.4 and is in DBSQL current.

SELECT DATEADD(HOUR,IFNULL(100, 0),current_date) AS Date_Created_Local

=> 2022-05-31T04:00:00.000+0000.

You can also use one of these casts to turn any wellformed string into an interval:

SELECT current_date + 'INTERVAL \'100\' HOUR'::INTERVAL HOUR;

SELECT current_date + CAST ('INTERVAL \'100\' HOUR' AS INTERVAL HOUR);