---
title: "CFAbsoluteTimeAddGregorianUnits(_:_:_:)"
framework: corefoundation
role: symbol
role_heading: Function
path: "corefoundation/cfabsolutetimeaddgregorianunits(_:_:_:)"
---

# CFAbsoluteTimeAddGregorianUnits(_:_:_:)

Adds a time interval, expressed as Gregorian units, to a given absolute time.

## Declaration

```swift
func CFAbsoluteTimeAddGregorianUnits(_ at: CFAbsoluteTime, _ tz: CFTimeZone!, _ units: CFGregorianUnits) -> CFAbsoluteTime
```

## Parameters

- `at`: The absolute time to which the interval is added.
- `tz`: The time zone to use for time correction. Pass NULL for GMT.
- `units`: The time interval to add to at.

## Return Value

Return Value An absolute time value equal to the sum of at and units.

## See Also

### Core Foundation Time Utilities Miscellaneous Functions

- [CFAbsoluteTimeGetCurrent()](corefoundation/cfabsolutetimegetcurrent().md)
- [CFAbsoluteTimeGetDayOfWeek(_:_:)](corefoundation/cfabsolutetimegetdayofweek(_:_:).md)
- [CFAbsoluteTimeGetDayOfYear(_:_:)](corefoundation/cfabsolutetimegetdayofyear(_:_:).md)
- [CFAbsoluteTimeGetDifferenceAsGregorianUnits(_:_:_:_:)](corefoundation/cfabsolutetimegetdifferenceasgregorianunits(_:_:_:_:).md)
- [CFAbsoluteTimeGetGregorianDate(_:_:)](corefoundation/cfabsolutetimegetgregoriandate(_:_:).md)
- [CFAbsoluteTimeGetWeekOfYear(_:_:)](corefoundation/cfabsolutetimegetweekofyear(_:_:).md)
- [CFGregorianDateGetAbsoluteTime(_:_:)](corefoundation/cfgregoriandategetabsolutetime(_:_:).md)
- [CFGregorianDateIsValid(_:_:)](corefoundation/cfgregoriandateisvalid(_:_:).md)