---
title: CFTimeZoneResetSystem()
framework: corefoundation
role: symbol
role_heading: Function
path: corefoundation/cftimezoneresetsystem()
---

# CFTimeZoneResetSystem()

Clears the previously determined system time zone, if any.

## Declaration

```swift
func CFTimeZoneResetSystem()
```

## Discussion

Discussion If the default time zone is set to the same value as the system time zone or has not been explicitly set, this function clears it as well. Subsequent calls to CFTimeZoneCopySystem() will attempt to re-determine the system time zone.

## 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)
- [CFTimeZoneSetDefault(_:)](corefoundation/cftimezonesetdefault(_:).md)
- [CFTimeZoneCopyKnownNames()](corefoundation/cftimezonecopyknownnames().md)
- [CFTimeZoneSetAbbreviationDictionary(_:)](corefoundation/cftimezonesetabbreviationdictionary(_:).md)