STARTOFWEEK
The first date of the week in the filter context; needs a calendar.
Part of the calendar-based time intelligence that Power BI added in 2025.
Group: Time intelligence. Compatible with DAX.
Syntax
STARTOFWEEK ( <calendar> )| Parameter | Type | Description |
|---|---|---|
calendar | Calendar | The name of a calendar defined in the model that has a week category. |
Returns
Table. The first date of the calendar's week.
Remarks
- It takes a calendar only: a column of dates is an error. A calendar is defined in the model on a date table and tags its columns as year, quarter, month, week, date and the like; the week is whatever the calendar's week column says, ISO weeks from Monday or a retail week.
- The week is the one of the first date in the filter context. With ISO weeks and Wednesday 13 March 2024 in the filter, it is Monday 11 March.
- The calendar must be able to read the filter context: one of weeks and dates without months cannot answer under a filter on a month, and the call is an error.
- The result holds the calendar's rows with all its tagged columns, so it is meant as a filter:
CALCULATE ( MIN ( 'Date'[Date] ), ... )gives one date from it.
Examples
Without a calendar
The Example Brewery defines no calendar, so a date column is all it can offer, and the call fails.
EVALUATE
ROW ( "Start of week", STARTOFWEEK ( Prices[Date] ) )Result: an error.