Sorry my example XLS is outdated, I had to dump the use of DAYS360 as it rounds the months to 30 day months. I now subtract the discharge date from the intake date to get total bed days. Prime example is row 30. Intake date and discharge date are the same. Subtracting discharge from intake dates will give me a total of "0". so I use a formula of [=IF(G30-F30=0,1,(G30-F30))] to force a count of "1". We bill for all days except the discharge date, so subtracting discharge from admit works. except when one checks in and out on the same day, I am still billing for one day, savvy? But now look at Cell P30. The index formulas count the bed days used within the month, but if the admit and discharge dates are the same, "0" will be the total. and throws off my billable days for the month by 1. This is where I get lost. not to familiar with circular references yet.