Total number of each month in a column of dates

[GeorgeF.]

I have a list of dates, mmm-dd-yy from which I want the total number of
occurrences of each month and the sum of associated expenses a couple of
columns to the right

 

[Frank Kabel]

Hi
1. Occurences:
=SUMPRODUCT(--(MONTH(A1:A100)=1),--(A1:A100<>""))

2. Sum:
=SUMPRODUCT(--(MONTH(A1:A100)=1),--(A1:A100<>""),B1:B100)

Also see:
http://www.xldynamic.com/source/xld.SUMPRODUCT.html