I need to create a formula that will count numbe rof months..Basically if you took this month ..then how many months back is the month in a certain cell..

What I came up with does that, but the only problem is its using a 30 day count..so that December shows up as both 1 and 2 months back..

Here is the formula I currently have: =MONTH(TODAY()-F189)

Notice how even though all of them are December some are counting as 1 month back and other are counted as 2 months back.. I tried using other functions like "now" but this is the closes I got to what I want... Would appreciate any help anyone can give me on this. Thanks.

date months back from current month
12/26/2013 2
12/26/2013 2
12/27/2013 2
12/30/2013 1
12/30/2013 1
12/30/2013 1
12/30/2013 1
12/31/2013 1
12/31/2013 1
12/31/2013 1
12/31/2013 1
12/31/2013 1
12/31/2013 1
12/31/2013 1