Week numbers in Microsoft Power BI

How to get the week number from a date

To get the ISO week number (1-53), use WEEKNUM(date, 2).

The second parameter, 2, is a code that identifies ISO week numbers among other week numbering scheme.

How to get the number of weeks in a year

To get the number of ISO weeks (i.e. the number of the last week) in a year, get the week number of 28 December in that year using the above logic, i.e. WEEKNUM(DATE(year, 12, 28), 2).

year contains the four-digit year (e.g. 2024).

This is based on the fact that the last week of the year always includes 28 December.

Read more

Learn more about week numbers and the ISO week numbering scheme in this little primer.