Thank you for the replies, I should add that when I say 'month', I mean a listing of month/year such as :

1/1996
2/1996
.
.
.
12/2016

The window of dates will slide as time goes on, so I didn't want to build a table of these and have to add on to it every so often to keep it up to date. Thats the kind of thing that is guarenteed to get forgotten someday.