starts a previously created whichTimer with timeout (seconds), periodic yes/no (repeats itself), that calls handlerFunc when timeout reaches 0.

It is affected by gamespeed at any point of it execution, if the gamespeed is changed at 50% of timeout duration, the rest of the timeout will be correctly affected by new gamespeed.

See: [jassdoc]GetExpiredTimer[/jassdoc] to retrieve the handle of expired timer inside handlerFunc