Counting data based on a date period eg. Month

Hi

I am wanting to know what formula to use if I want to count the different types of source referrals for clients in a particular month eg. how many clients for December were casefind and how many referrals. For example, the list appears like this:-

Date Client Source
28/12/2007 Client A Referral
29/12/2007 Client B CaseFind
1/1/2008 Client C CaseFind
1/1/2008 Client D CaseFind
2/2/2008 Client E Referral

To count the number of CaseFinds I would expect an answer under the heading December of '1' for January '2'.

I have been working on the following formula
=sumproduct((A1:A119=datevalue(?????))*(C1:C119="Casefind"))
but can not workout how to get the system to count entries for one month only eg. December. The formula works if I enter in one date only eg. 29/12/2007. Can someone please help me with this formula or maybe suggest a complete new approach?

Many thanks

jennyp

Hi

Thanks for your response. The formula you provided below works perfectly however if the database goes across two calender years what formula do I need for Excel to differentiate between December 07 and December 08.

=sumproduct(--month(A1:A5)=12)*(C1:C5="CaseFind")

Many thanks.

jennp

You can either add another test for the year, like this

=sumproduct((month(A1:A5)=12)*(year(A1:A5)=2007)*( C1:C5="CaseFind"))

or do both together like this

=sumproduct((text(A1:A5,"mmmyy")="dec07")*( C1:C5="CaseFind"))