# Timer Calls

This chapter lists timer calls in alphabetical order. The list below is a quick summary of each, followed by the page number where you'll find the procedure described.

- `AddTimes` Adds two time values together.
- `CompareTimes` Compares two time values.
- `CreateTimerIOReq` Creates a timer device I/O request.
- `DeleteTimerIOReq` Delete a timer device I/O request.
- `SubTimes` Subtracts one time value from another.
- `TimeLaterThan` Returns whether a time value comes before another.
- `TimeLaterThanOrEqual` Returns whether a time value comes before or at the same time as another.
- `WaitTime` Waits for a given amount of time to pass.
- `WaitUntil` Waits for a given amount of time to pass.