Thanks for your reply. That was useful
Note that some months may have six weeks in them, so you'll need to modify the nested IF statements above.
If you are looking for the calendar week by month:
DATEPART('week', [Order Date]) - DATEPART('week', DATETRUNC('month',[Order Date])) + 1
You'll want to convert this calc to a Dimension.
Using this, March 4, 2018 would be "2"
If you are looking to count each group of 7 days (like the IF statements above), you could try this quickie:
Using this, March 4, 2018 would be "1"
Good luck! --Michael