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# addTimeInterval(_:)

Adds a time interval to this date.

```
mutating func addTimeInterval(_ timeInterval: TimeInterval)
```

## Parameters

`timeInterval`

The value to add, in seconds.

## Discussion

> Warning:
> This only adjusts an absolute value. If you wish to add calendrical concepts like hours, days, months then you must use a `Calendar`. That will take into account complexities like daylight saving time, months with different numbers of days, and more.

---

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