A timer specification declares when a PTimerWentOffEvent should be sent. These events are sent to the listeners registered on the specification. PTimer specifications may be absolute or delayed .
Absolute specifications go off at the specified time.
Delayed specifications go off after waiting the specified amount of time. Delayed specifications may be repeating or non-repeating. Repeating specifications automatically reschedule theselves after going off. Repeating specifications may be regular or non-regular. Regular specifications attempt to go off at fixed intervals of time, irrespective of system load or how long it takes to notify the listeners.