If you subtract two times, the result is a duration that represents the number of hours, minutes, and seconds between the two times. A negative result is possible when subtracting two times.
If you want to know how much time an interview for a person with temporary ID 410 took, use this SQL statement:
SELECT ENDTIME - STARTTIME FROM Q.INTERVIEW WHERE TEMPID = 410
QMF produces this report:
+--------------------------------------------------------------------------------+ | COL1 | | --------- | | 11800 | +--------------------------------------------------------------------------------+
The result is a numeric representation of the duration: 1 hour, 18 minutes, and 0 seconds. You can treat this result like any other numeric value. The duration format for time is hhmmss, where hh represents hours, mm represents minutes, and ss represents seconds. QMF always removes leading zeros from the result.