---
title: "CFTimeZoneCopyAbbreviation(_:_:)"
framework: corefoundation
role: symbol
role_heading: Function
path: "corefoundation/cftimezonecopyabbreviation(_:_:)"
---

# CFTimeZoneCopyAbbreviation(_:_:)

Returns the abbreviation of a time zone at a specified date.

## Declaration

```swift
func CFTimeZoneCopyAbbreviation(_ tz: CFTimeZone!, _ at: CFAbsoluteTime) -> CFString!
```

## Parameters

- `tz`: The time zone to use.
- `at`: The absolute time at which to obtain the abbreviation.

## Return Value

Return Value A string containing the time zone abbreviation of at. Ownership follows the The Create Rule.

## Discussion

Discussion Note that the abbreviation may be different at different dates. For example, during daylight savings time the US/Eastern time zone has an abbreviation of “EDT.” At other times, its abbreviation is “EST.”

## See Also

### System and Default Time Zones and Information

- [CFTimeZoneCopyAbbreviationDictionary()](corefoundation/cftimezonecopyabbreviationdictionary().md)
- [CFTimeZoneCopyDefault()](corefoundation/cftimezonecopydefault().md)
- [CFTimeZoneCopySystem()](corefoundation/cftimezonecopysystem().md)
- [CFTimeZoneSetDefault(_:)](corefoundation/cftimezonesetdefault(_:).md)
- [CFTimeZoneCopyKnownNames()](corefoundation/cftimezonecopyknownnames().md)
- [CFTimeZoneResetSystem()](corefoundation/cftimezoneresetsystem().md)
- [CFTimeZoneSetAbbreviationDictionary(_:)](corefoundation/cftimezonesetabbreviationdictionary(_:).md)