---
title: timeZone
framework: foundation
role: symbol
role_heading: Instance Property
path: foundation/iso8601dateformatter/timezone
---

# timeZone

The time zone used to create and parse date representations. When unspecified, GMT is used.

## Declaration

```swift
var timeZone: TimeZone! { get set }
```

## Discussion

Discussion Resetting this property can incur a significant performance cost, as it may cause internal state to be regenerated.

## See Also

### Configuring the Formatter

- [formatOptions](foundation/iso8601dateformatter/formatoptions.md)