---
title: "CFTimeZoneSetDefault(_:)"
framework: corefoundation
role: symbol
role_heading: Function
path: "corefoundation/cftimezonesetdefault(_:)"
---

# CFTimeZoneSetDefault(_:)

Sets the default time zone for your application the given time zone.

## Declaration

```swift
func CFTimeZoneSetDefault(_ tz: CFTimeZone!)
```

## Parameters

- `tz`: The time zone to use as default.

## Discussion

Discussion There can be only one default time zone, so by setting a new default time zone, you lose the previous one.

## See Also

### System and Default Time Zones and Information

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