CURRENT TIMEZONE special register
The CURRENT TIMEZONE (or CURRENT_TIMEZONE) special register specifies the difference between UTC (Coordinated Universal Time, formerly known as GMT) and local time at the application server.
The difference is represented by a time duration (a decimal number in which the first two digits are the number of hours, the next two digits are the number of minutes, and the last two digits are the number of seconds). The number of hours is between -24 and 24 exclusive. Subtracting CURRENT TIMEZONE from a local time converts that local time to UTC. The time is calculated from the operating system time at the moment the SQL statement is executed. (The CURRENT TIMEZONE value is determined from C runtime functions.)
The CURRENT TIMEZONE special register can be used wherever an expression of the DECIMAL(6,0) data type is used; for example, in time and timestamp arithmetic.
When used in an SQL statement inside a routine, CURRENT TIMEZONE is not inherited from the invoking statement.
INSERT INTO IN_TRAY VALUES ( CURRENT TIMESTAMP - CURRENT TIMEZONE, :source, :subject, :notetext )