---
title: rollingPeriod
framework: exposurenotification
role: symbol
role_heading: Instance Property
path: exposurenotification/entemporaryexposurekey/rollingperiod
---

# rollingPeriod

The length of time that this key is valid.

## Declaration

```swift
var rollingPeriod: ENIntervalNumber { get set }
```

## Discussion

Discussion important: This property is available in iOS 12.5, and in iOS 13.5 and later. The value of this property is the number of 10-minute windows between key rolling.

## See Also

### Exposure Criteria

- [transmissionRiskLevel](exposurenotification/entemporaryexposurekey/transmissionrisklevel.md)
- [keyData](exposurenotification/entemporaryexposurekey/keydata.md)
- [rollingStartNumber](exposurenotification/entemporaryexposurekey/rollingstartnumber.md)
- [ENIntervalNumber](exposurenotification/enintervalnumber.md)