Date Problem-See attached Excel Sheet

I'm having a problem with a date range giving the wrong solution. Open the spreadsheet for detail.

Thanks in advance for any help. I'm using Excel 2007. I'm also a beginner.

Thanks for you help. I'm new enough to Excel that I may not of understood your suggestion. This is what I did:

I removed: =IF(C7<=DATEDIF($B$3,$B$4,"M")+(DATEDIF($B$3,$B$4,"md")>0),$B$5,0)

and replaced all of it with =IF(EDATE($B$3,C7-1)>$B$4,0,$B$5).


This worked by giving the correct number of months, 12, but when I changed the begin date from 1/1/2015 to 1/2/2015 it returned to the incorrect number 11.