---
title: timeIntervalSinceReferenceDate
framework: foundation
role: symbol
role_heading: Instance Property
path: foundation/date/timeintervalsincereferencedate-swift.property
---

# timeIntervalSinceReferenceDate

The interval between the date value and 00:00:00 UTC on 1 January 2001.

## Declaration

```swift
var timeIntervalSinceReferenceDate: TimeInterval { get }
```

## Discussion

Discussion This property’s value is negative if the date object is earlier than the system’s absolute reference date (00:00:00 UTC on 1 January 2001).

## See Also

### Getting Time Intervals

- [timeIntervalSince(_:)](foundation/date/timeintervalsince(_:).md)
- [timeIntervalSinceNow](foundation/date/timeintervalsincenow.md)
- [timeIntervalSince1970](foundation/date/timeintervalsince1970.md)
- [timeIntervalSinceReferenceDate](foundation/date/timeintervalsincereferencedate-swift.type.property.md)
- [timeIntervalBetween1970AndReferenceDate](foundation/date/timeintervalbetween1970andreferencedate.md)
- [Date.Stride](foundation/date/stride.md)