__TimerEvent class

The __TimerEvent system class is reports an event generated by WMI in response to a consumer's request for an interval timer event or an absolute timer event. An interval timer event is an event that occurs at regular intervals. An absolute timer event is an event that occurs at a specific time. Timer events can occur in any namespace.

The following syntax is simplified from Managed Object Format (MOF) code and includes all inherited properties. Properties are listed in alphabetic order, not MOF order.


class __TimerEvent : __Event
  uint32 NumFirings;
  string TimerId;
  uint64 TIME_CREATED;


The __TimerEvent class has these types of members:


The __TimerEvent class has these properties.


Data type: uint32

Access type: Read-only

Number of times the event occurred before a notification was delivered to the consumer.


Data type: uint8 array

Access type: Read-only

Descriptor used by the event provider to determine which users can receive the event. This property is inherited from __Event.


Data type: uint64

Access type: Read-only

Unique value that indicates the time at which the event was generated. This is a 64-bit value that represents the number of 100-nanosecond intervals after January 1, 1601. The information is in the Coordinated Universal Times (UTC) format. This property is inherited from __Event.

For more information about using uint64 values in scripts, see Scripting in WMI.


Data type: string

Access type: Read-only

Instance of the __TimerInstruction subclass that caused WMI to fire this event. Consumers specify a timer identification in the TimerId property of the __TimerInstruction subclass that they create to register.


The __TimerEvent class is derived from __Event.

Event consumers register for an absolute timer event by creating an instance of the __AbsoluteTimerInstruction system class. They register for an interval timer event by creating an instance of the __IntervalTimerInstruction system class.

During normal operation, the NumFirings property is set to 1. When it is not possible to reach the consumer or the firing interval is much quicker than the ability to deliver the event, NumFirings is set to a number greater than 1. When NumFirings is greater than 1, WMI automatically merges many timer events into the same event. This merging is similar to what occurs with WM_TIMER messages in Windows programming.


Requirement Value
Minimum supported client
Windows Vista
Minimum supported server
Windows Server 2008
All WMI namespaces

See also


WMI System Classes

Receiving Timed or Repeating Events

Receiving Events at All Times

Receiving Events for the Duration of Your Application