Problem:

How to formulate Last n days in DAX?

Solution:

It can be achieved using the combination of CALCULATE & DATESINPERIOD function.

Formula to sum up values for last 10 days

[code type=”sql”]
MeasureName:=CALCULATE(SUM([YourColumnName]),DATESINPERIOD(Calendar[DateKey],TODAY(),-10,day))
[/code]

Note the use of a calendar table in the DATESINPERIOD. It is pretty common to have a “date” dimension & I’ve used it the DateKey from the dimension as the “date” column which is required by the DATESINPERIOD function.

You can use the above example as a starting point now.