I'm using a sumproduct function to count how many times a combination of 2
criteria occur at the same time across a range.

Col A contains month and year and is custom formatted as mmm-yy eg Jan-08
Col B contains a numerical value eg £100 .

Im using
=SUMPRODUCT((TEXT(A1:A100,"mmm-yy")="Jan-08")*(B1:B1000)) which counts how
many occurances of Jan-08 there are with a value of over 0.

I also need to know:

1. how to calculate the total of all the values in Col B when both my
criteria
are met. eg. sum of col B entries when Col A is Jan-08 and Col B has an
entry of any value in it. Any thoughts on how I amend the sumproduct
function to sum rather than count when two criteria are met.

2. Also, by using the 0 in my function, it then doesn't include any 0
entries I might have in Col B. I changed the formula to =0 at the end as
follows
=SUMPRODUCT((TEXT(A1:A100,"mmm-yy")="Jan-08")*(B1:B100=0))
but it then included the cells that were blank too (I only want them to be
included in my count if I have a numerical value in the cell). Is there a
way of setting the 2nd criteria to be a value or entry of any numerical
value, even zero, perhaps by adding a wildcard*.

Thanks for any help you can offer.

--
KJ