Date.DayOfWeek is a function in the Power Query M language that returns a number from 0 to 6 indicating the day of the week of the provided value. The function accepts a parameter to specify which day should be considered the first day of the week.
Compatible with: Power BI Service Power BI Desktop Excel Microsoft 365
Syntax
Date.DayOfWeek(
dateTime as any,
optional firstDayOfWeek as nullable number,
) as nullable number| Argument | Attribute | Description |
|---|---|---|
| dateTime | A date, datetime or datetimezone value. | |
| firstDayOfWeek | optional | The Day.Type specifies the starting day of the week. If not explicitly specified, the function defaults to a culture-dependent day, aligning with regional week-start norms. It accepts values representing each day: – Day.Sunday (0) for Sunday, – Day.Monday (1) for Monday, – Day.Tuesday (2) for Tuesday, – Day.Wednesday (3) for Wednesday, – Day.Thursday (4) for Thursday, – Day.Friday (5) for Friday, – Day.Saturday (6) for Saturday. |
Description
Returns a number (from 0 to 6) indicating the day of the week of the provided dateTime.
Examples
Get the day of the week represented by Monday, February 21st, 2011, treating Sunday as the first day of the week.
// Output: 1
Date.DayOfWeek( #date( 2011, 02, 21 ), Day.Sunday )Get the day of the week represented by Monday, February 21st, 2011, treating Monday as the first day of the week.
// Output: 0
Date.DayOfWeek( #date( 2011, 02, 21 ), Day.Monday )Related articles
Learn more about Date.DayOfWeek in the following articles:
- Create ISO Week and ISO Year in Power Query M (ISO 8601)
Learn how to create ISO Week and Year numbers in Power Query for consistent weeks and fiscal calendars. Step-by-step tutorial included! » Read more - Return Next Working Day in Power Query
Do you want to return the next working day in Power Query? There is no build in M-function for this, but this post shows how to create one yourself! » Read more - Create Date Table or Calendar in Power Query M
Learn how to create a dynamic calendar table in Power Query’s M language. Build your custom columns and claim your free Date Table Script. » Read more
Related functions
Other functions related to Date.DayOfWeek are:
- Date.Day
- Date.DayOfYear
- Date.DaysInMonth
- Date.Month
- Date.QuarterOfYear
- Date.WeekOfMonth
- Date.WeekOfYear
- Date.Year
