How to start week in Power BI from Friday

I need to create a biweekly interval where Friday is first day of the week. I am stuck at trying to figure out if there's a function that will allow moving first day of the week to Friday.

I have tried the WEEKDAY() function, but it only allows start dates between Saturday, Sunday, Monday.

Solution

You could create a DAX Calculated Column with this:

Week Starting (fri) = 
  var wkd = WEEKDAY([Date], 2)
  return [Date] + IF(wkd > 4, 5, -2) - wkd

This will return the previous Friday date.