Count how many times a month appear but ignore blank cells

hai

i have big issue which i couldn't clear it.

date A ----------------- date B
2-jan-2011 -------- 5-jan-2011
5-jan-2011 ------- 7-jan-2011
7-may-2011 ---------
8-may-2011 ------- 9-may-2011
2-feb-2011 --------5-feb-2011
2-feb-2011 ----- 8-feb-2011
2-apr-2011


1. = i want to count how many times a months appear in (date A)

2.=if i put date B same months which is in date A that i have to count separately.


3.= deferent months in date B that i have to count separately.


Please help me to solve this problem


thank you.