This statement changes the time zone displacement for user pa from whatever it had been to the time zone displacement defined by the string 'America Pacific' using the TIME ZONE = ‘time_zone_string’ option.
Vantage passes the specified time zone string to a system-defined UDF that validates it. The UDF is also called to retrieve the rules associated with the time zone string whenever pa logs on.
MODIFY USER pa AS TIME ZONE = 'America Pacific';
If the value of the time_zone_string you specify is not valid, Vantage returns an error to the requestor.