countif with date ranges of indeterminate length

[kualjo]

I am having trouble writing a COUNTIF formula that will tell me how many times a particular month appears in a list of dates. January may appear 10 times, February may appear 43 times, March 102 times, etc. Instead of manually selecting the range for each month and using the count feature on the status bar, I need a formula that will count for me. I tried:
COUNTIF(B:B,month(1))
COUNTIF(B:B,month=1)
as well as several other lame attempts, but kept getting a result of zero or an error. What am I missing here?

 

[DonkeyOte]

To account for blanks either:

Add an ISNUMBER test

=SUMPRODUCT(--(ISNUMBER($B$2:$B$1000)),--(MONTH($B$2:$B$1000)=1),--(YEAR($B$2:$B$1000)=2009))

or use a TEXT coercion

=SUMPRODUCT(--(TEXT($B$2:$B$1000,"MMYY")="0109"))