---
title: duration()
framework: healthkit
role: symbol
role_heading: Instance Method
path: healthkit/hkstatistics/duration()
---

# duration()

Returns the total duration covering all the samples that match the query.

## Declaration

```swift
func duration() -> HKQuantity?
```

## Discussion

Discussion If you set the duration option, this method returns a quantity object containing total duration covering all the samples that match the query; otherwise, it returns nil.

## See Also

### Getting Statistics Data

- [averageQuantity()](healthkit/hkstatistics/averagequantity().md)
- [averageQuantity(for:)](healthkit/hkstatistics/averagequantity(for:).md)
- [maximumQuantity()](healthkit/hkstatistics/maximumquantity().md)
- [maximumQuantity(for:)](healthkit/hkstatistics/maximumquantity(for:).md)
- [minimumQuantity()](healthkit/hkstatistics/minimumquantity().md)
- [minimumQuantity(for:)](healthkit/hkstatistics/minimumquantity(for:).md)
- [sumQuantity()](healthkit/hkstatistics/sumquantity().md)
- [sumQuantity(for:)](healthkit/hkstatistics/sumquantity(for:).md)
- [duration(for:)](healthkit/hkstatistics/duration(for:).md)