Help, whether the Ontimer function can be started regularly?

 
I wrote a 15 minute timer(15*60), but I want to make the onTimer() start regularly, for example, 00:15, 00:30, 00:45.
How should it be realized?
Thanks very much!
 
Use a one minute or one second timer, and have OnTimer filter to every 15 minutes.
void OnTimer(){
   static datetime nextRun=0;
   datetime now=TimeCurrent();
   if(now < nextRun) return;
   nextRun = now - now % 900 + 900; // Every quarter-hour.
   ⋮
 
William Roeder #:
Use a one minute or one second timer, and have OnTimer filter to every 15 minutes.

thanks!

Reason: