Michael,
Suppose your list of dates are in the range A1:A100. In cells B1:B12 enter
the numbers 1 through 12, indicating months. Then, in C1, enter
=SUM(IF($A$1:$A$100=0,0,--(MONTH($A$1:$A$100)=B1)))
and press CTRL SHIFT ENTER rather than just ENTER. Copy this formula down
from C1 through C12. The formula will return the number of dates in A1:A100
that are in the month listed in column B.
Note that this is an array formula, so you must press CTRL SHIFT ENTER
rather than just ENTER when you first enter the formula and whenever you
edit it later. If you do not do this, the result will be incorrect. If you
do this properly, Excel will display the formula enclosed in curly braces
{ }. See
http://www.cpearson.com/Excel/ArrayFormulas.aspx for much more
information about array formulas.
--
Cordially,
Chip Pearson
Microsoft Most Valuable Professional
Excel Product Group
Pearson Software Consulting, LLC
www.cpearson.com
(email on web site)