I have entered the following formula on a summary sheet:

SUMPRODUCT(('issue detail'!MONTH(A$3:A$275)=7)*('issue detail'!B$3:B$275))

Issue Detail is the second sheet in the workbook. Column A contains dates
(every day of the year). Columns B thru E contain numbers. I am trying to
get a total for the month of July (and for all other months) for each column.
This formula keeps retuning zero. Why?

If I can get the formula to work, I would also break down the totals by
week. By the end of the year, with 12 months and 52 weeks, would another
formula be faster?

I am using Excel 2003.

Thanks, Ron