---
title: calendarDayChanged
framework: foundation
role: symbol
role_heading: Type Property
path: foundation/notificationcenter/messageidentifier/calendardaychanged
---

# calendarDayChanged

An identifier for a message about a change in calendar day.

## Declaration

```swift
static var calendarDayChanged: NotificationCenter.BaseMessageIdentifier<Calendar.CalendarDayChangedMessage> { get }
```

## Discussion

Discussion Use this identifier with NotificationCenter’s addObserver(of:for:using:) or messages(of:for:bufferSize:) methods to observe messages of type Calendar.CalendarDayChangedMessage.

## See Also

### Identifying calendar, date, and time zone messages

- [systemClockDidChange](foundation/notificationcenter/messageidentifier/systemclockdidchange.md)
- [systemTimeZoneDidChange](foundation/notificationcenter/messageidentifier/systemtimezonedidchange.md)