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# DispatchTimeInterval

A number of seconds, millisconds, microseconds, or nanoseconds.

```
enum DispatchTimeInterval
```

## Overview

Use [`DispatchTimeInterval`](/documentation/Dispatch/DispatchTimeInterval) values to specify the interval at which a [`DispatchSourceTimer`](/documentation/Dispatch/DispatchSourceTimer) fires or I/O handlers are invoked for a [`DispatchIO`](/documentation/Dispatch/DispatchIO) channel, as well as to increment and decrement [`DispatchTime`](/documentation/Dispatch/DispatchTime) values.

## Topics

### Enumeration Cases

[`DispatchTimeInterval.seconds(_:)`](/documentation/Dispatch/DispatchTimeInterval/seconds(_:))

A number of seconds.

[`DispatchTimeInterval.milliseconds(_:)`](/documentation/Dispatch/DispatchTimeInterval/milliseconds(_:))

A number of milliseconds.

[`DispatchTimeInterval.microseconds(_:)`](/documentation/Dispatch/DispatchTimeInterval/microseconds(_:))

A number of microseconds.

[`DispatchTimeInterval.nanoseconds(_:)`](/documentation/Dispatch/DispatchTimeInterval/nanoseconds(_:))

A number of nanoseconds.

[`DispatchTimeInterval.never`](/documentation/Dispatch/DispatchTimeInterval/never)

No interval.

### Operator Functions


---

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