When you create an external procedure, Vantage stores the current session time zone for the procedure along with its definition to enable the SQL language elements in the procedure to execute in a consistent time zone and produce consistent results. However, time or timestamp data passed as an input parameter to the procedure still use the runtime session time zone rather than the creation time zone for the procedure.
The AT TIME ZONE option enables you to reset the time zone for all of the SQL elements of external procedures when you recompile a procedure. Vantage then stores the newly specified time zone as the creation time zone for the procedure.
You can only specify AT TIME ZONE with the COMPILE [ONLY] option, and it must follow the COMPILE [ONLY] specification. Otherwise, the system returns an error to the requestor.