=SUMPRODUCT(--(MONTH(C2:C100)=1),--(MONTH(C2:C100<=2),B2:B100)

Where 1 represents Jan, and 2 represents February. If you want only 1 months
data, change btoh of these numbers to the same value.

--
Best Regards,

Luke M
"dgnamu" wrote in message
...

hi,

can someone helps me to solve this problem?

name no books read month
nasir 1 12-jan-2010
adam 2 12-jan-2010
fatima 3 14-jan-2010
nasir 2 2-feb-2010
adam 1 2-feb-2010
fatima 1 3-feb-2010
nasir 1 7-mar-2010
adam 4 16-mar-2010
fatima 1 21-mar-2010
nasir 1 17-apr-2010
adam 4 18-apr-2010
fatima 1 24-apr-2010

now, what i'm doing is i'm just selecting the specific month and do the
counting. The formula is Sum(B2:B4) for january. this come to a problem if
the array is not sort accordingly.

what i want is, i'm trying to get the total no of book read in a specific
month like jan or mar. but the formula should cover from jan-apr. please
someone helps me to generate the formula.