Are you using Excel 2007? If not, then you can't use entire columns as range
references in SUMPRODUCT.

I'd use a cell to hold the date criteria.

A1 = some date like 1/1/2010

Then:

=SUMIF('Jan-Jun'!F:F,"="&A1,'Jan-Jun'!I:I)

--
Biff
Microsoft Excel MVP


"joemeshuggah" wrote in message
...
i am trying to sum column i on a particular worksheet where the date in
column f is greater than or equal to the beginning of the month. the
formula
i have is as follows...

=SUMPRODUCT(--'Jan-Jun'!I2:I65536,--'Jan-Jun'!F:F=(TODAY()-(DAY(TODAY())-1)))

the result is a #num! error...where is my formula incorrect?