BigIron,

There are many ways, the one I would use is this:

- Defne a calculated column in the date table, which contains the value of the previous date
- Using CALCULATE, you can compute the sum of amount, in the filter context of the current date, using the previous one

Then, it is a matter of a subtraction. Clearly, all these formulas will work only if COUNTROWS(VALUES(Date[DateId])) = 1, otherwise they should be blanked.

If you need the formulas, please share the workbook, just to make my life easier. :)

Alberto Ferrari

http://www.powerpivotworkshop.com