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ISO and Broadcast Calendars

DayPicker can follow different week numbering systems. You can switch to ISO 8601 week numbering or to the US broadcast calendar, which both override the default week rules from the current locale.

Use only one of these systems at a time: ISOWeek or broadcastCalendar.

ISO 8601 calendar

Use the ISOWeek prop to switch to ISO week dates. With ISO 8601:

  • Weeks always start on Monday.
  • Week 1 is the week that contains the first Thursday of the year.
  • Week numbers follow the ISO standard instead of locale-specific rules.
<DayPicker ISOWeek showWeekNumber />

Broadcast calendar

Use the broadcastCalendar prop to switch to the US broadcast calendar, commonly used in the TV and radio industry. In this system:

  • Weeks start on Monday.
  • Week 1 starts with the first Monday of the calendar year.
  • Months are displayed as 4 or 5 complete broadcast weeks.
<DayPicker broadcastCalendar showWeekNumber />