---
title: "intervalWillStartWarning(for:)"
framework: Device Activity
role: symbol
role_heading: Instance Method
platforms: [iOS 15.0+, iPadOS 15.0+, Mac Catalyst 15.0+]
path: "deviceactivity/deviceactivitymonitor/intervalwillstartwarning(for:)"
---

# intervalWillStartWarning(for:)

Warns your app of an upcoming activity a specified time before the activity starts.

## Declaration

```swift
func intervalWillStartWarning(for activity: DeviceActivityName)
```

## Parameters

- `activity`: The name of the activity.

## Discussion

Discussion When an activity is about to start, intervalWillStartWarning warns your app extension of the upcoming activity.

## See Also

### Monitoring Scheduled Intervals

- [intervalDidEnd(for:)](deviceactivity/deviceactivitymonitor/intervaldidend(for:).md)
- [intervalDidStart(for:)](deviceactivity/deviceactivitymonitor/intervaldidstart(for:).md)
- [intervalWillEndWarning(for:)](deviceactivity/deviceactivitymonitor/intervalwillendwarning(for:).md)