When a DATETIME or a DATETIME-TZ value is defined to a table in the DataServer schema without a default value, its initial value is automatically set to "?" (the Unknown value). An option for setting the initial value is to use the ABL NOW function. It initializes both date and time parts of the current date and time and the time zone portion for DATETIME-TZ columns. Using NOW for initialization sets the date, time, and time zone based on SESSION:TIME-SOURCE.