A Rolling 12 Month Sum Formula

[Deanwilson]

So we are working on a little tracking project and would like to have a formula that will provide a rolling 12 month total. For example, Jane had 10 points from 02/2010 and another 5 points from 06/2010 and 10 points from 01/2011. In light of it currently being March 2011 I am looking to write a formula that just reviews the last 12 calendar months and would result in 15 as the correct answer here....not 25. I rarely utilize date functions and this may be a no brainer to you folks but I would certainly appreciate any help.

 

[texasalynn]

looking at this

I adapted it to

Excel Workbook
	A	B	C	D
1	Date	Amount
2	Feb-2010	10
3	Jun-2010	5		15
4	Jan-2011	10
5
Sheet2

Excel 2003

Cell Formulas
Range	Formula
D3	=SUMPRODUCT(--(ABS(12*(2010-YEAR(A$2:A$10000))+5.5 -MONTH(A$2:A$10000)+ROWS(D$1:D1))<6),B$2:B$10000)