<!--
{
  "availability" : [
    "iOS: 2.0.0 - 8.0.0",
    "iPadOS: 2.0.0 - 8.0.0",
    "macCatalyst: 13.1.0 - 13.1.0",
    "macOS: 10.4.0 - 10.10.0",
    "tvOS: 9.0.0 - 9.0.0",
    "visionOS: 1.0.0 - 1.0.0",
    "watchOS: 2.0.0 - 2.0.0"
  ],
  "documentType" : "symbol",
  "framework" : "CoreFoundation",
  "identifier" : "/documentation/CoreFoundation/CFAbsoluteTimeAddGregorianUnits(_:_:_:)",
  "metadataVersion" : "0.1.0",
  "role" : "Function",
  "symbol" : {
    "kind" : "Function",
    "modules" : [
      "Core Foundation"
    ],
    "preciseIdentifier" : "c:@F@CFAbsoluteTimeAddGregorianUnits"
  },
  "title" : "CFAbsoluteTimeAddGregorianUnits(_:_:_:)"
}
-->

# CFAbsoluteTimeAddGregorianUnits(_:_:_:)

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

```
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

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

## Discussion

---

Copyright &copy; 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)