Proper Counting of Days

I am using Excel 2003 to create a spreadsheet to show how many billable days for a consumer's stay. If, the admit date is equal to the discharge date, the total comes out zero. I have worked out that issue. Now I want to show how many billable days broken down by month. The index will not show a sum of 1 if the admit date is the same as the discharge date. Having the same dates is not a common occurrence, but it does happen. See the yellow highlighted row for my example.

Thanks!