Power Query and DAX produce different week numbers for the same date

[Anonymous]

Hi community,

For at least the following date power query and DAX produce different week numbers:

date	weeknum_pq	weeknum_dax
Sunday, 4 September 2022	37	36

Weeknum_pq was produced by using the add column -> 'week of year' function

Weeknum_dax was produced by using:

weeknum_dax =
   WEEKNUM('table1'[date])

Is anyone experiencing the same issue? Or am I missing something in the way DAX and Power Query tackle week numbers, I could not find anything online that related to this issue.

Thanks in advance.

[tackytechtom · Accepted solution]

Hi @Anonymous ,

Have you tried playing around with the <return_type> option of the DAX formular WEEKNUM?

WEEKNUM function (DAX) - DAX | Microsoft Docs

For instance, it could be that your DAX formular uses Monday as the first day of week, while your Power Query uses Sunday.

Also, did you use the Date.WeekOfYear function in PQ? Here, there are also some settings that you can tweak to make them align:

Date.WeekOfYear - PowerQuery M | Microsoft Docs

Lastly, I believe in some cultures the first week of the year always falls on the first Monday and in other cultures the first week is determined by the first Thursday (ISO 8601). This can also be confusing sometimes.

Hope this helps!

/Tom
https://www.tackytech.blog/
https://www.instagram.com/tackytechtom/