The format of an &SETTIME event is as follows:

The seconds parameter represents the number of seconds since the epoch, 1st January 1970. For example:

&SETTIME(0) sets the time to Thu Jan 1 00:00:00.0 BST 1970.

&SETTIME(1185874846.3) sets the time to Tue Jul 31 09:40:46.3 BST 2007.

Normally, you do not need to send &SETTIME events. You would just send &TIME events. An &SETTIME event is useful only to avoid the problem pattern described above. The only difference between an &SETTIME event and an &TIME event is that the &SETTIME event causes an intermediate, repeating timer to fire only once while the &TIME event causes intermediate, repeating timers to fire repeatedly. For example, on all wait(0.1) fires ten times for every second in the difference between consecutive &TIME events. However, it fires only once when the correlator receives an &SETTIME event.

If you decide to send an &SETTIME event before an &TIME event, you typically want to send the &SETTIME event only before the first &TIME event. You should not send an &SETTIME event before subsequent &TIME events. Doing so causes a jumpy quality in the behavior of time. There is a warning message in the correlator log if you set a time that moves time backwards.

For information about when you might want to use external time events, see Determining whether to disconnect slow receivers in Deploying and Managing Apama.