dynamic days

abc_777 , You can use what of parameter for that

https://docs.microsoft.com/en-us/power-bi/desktop-what-if

example

 Rolling N day = CALCULATE(sum(Sales[Sales Amount]),DATESINPERIOD('Date'[Date],max('Date'[Date]),-1* selectedvalue(whatif[value]) ,Day)) 

Hi abc_777 

Please correct me if I wrongly understood your question.

Take 'Calendar Date'[Date] as the standard, and then calculate the date of the previous few days . I've taken the previous three days as an example .

Sum last 3 days = CALCULATE(SUM('Table'[sales]),FILTER('Table','Table'[Date]>CALCULATE(MAX('Calendar Date'[Date])-3) && 'Table'[Date]<=MAX('Calendar Date'[Date])))

Original data :

The effect is as shown:

Best Regards

Community Support Team _ Ailsa Tao

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