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# firstDayOfWeek

The first day of the week as represented by this locale.

```
var firstDayOfWeek: Locale.Weekday?
```

## Discussion

This value is the preferred first day of the week to show in a calendar view. It isn’t necessarily the same as the first day after the weekend; don’t try to determine a first-day-of-week value from weekend information.

Set this property to override the locale’s default first day of week. To request the default first day of week used by the locale, use the [`Locale`](/documentation/Foundation/Locale) property `firstDayOfWeek`.

This property corresponds to the `fw` key of the Unicode BCP 47 extension.

---

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