One way...

Use cells to hold the dates of your boundaries.

D1 = lower date boundary = 12/1/2009
E1 = upper date boundary = 12/31/2009

Column A contains the dates
Column B contains the values to sum

=SUMIF(A1:A20,"="&D1,B1:B20)-SUMIF(A1:A20,""&E1,B1:B20)

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Biff
Microsoft Excel MVP


"Orange Fuel" <Orange wrote in message
...
I have two columns. First column contains dates, second column contains
numbers. I want to sum all numbers for a specific month and year (i.e.
sum
all cells with date of 12-2009)

Thanks.