The schedule-timer-relative function schedules a timer to expire at a given time after the call to the function. The timer argument is a timer returned by make-timer or make-named-timer. The relative-expiration-time argument is a non-negative real number of seconds after the call to the function at which the timer is to expire. If repeat-time is specified, it is a non-negative real number of seconds that specifies a repeat interval. Each time the timer expires, it is rescheduled to expire after this repeat interval.
If the timer is already scheduled to expire at the time this function is called, it is rescheduled to expire at the time specified by the relative-expiration-time argument. If that argument is nil , the timer is not rescheduled, but the repeat interval is set to the interval specified by the repeat-time argument.
The function schedule-timer schedules a timer to expire at a time relative to the start of the program.
The following example schedules a timer to expire 5 seconds after the call to schedule-timer-relative and every 5 seconds thereafter.
(setq timer
(mp:make-timer 'print 10 *standard-output*))
#<Time Event : PRINT> (mp:schedule-timer-relative timer 5 5) #<Time Event : PRINT> make-named-timer, make-timer, schedule-timer, schedule-timer-milliseconds, schedule-timer-relative-milliseconds, timer-expired-p, timer-name, unschedule-timer