Date Period & Number of Months it Indicates.

I am in need of coming up with a formula that will give me an answer as to how many months are represented between two dates written in excel.

I have the dates in two different cells but the number of months that needs to come out of the formula needs to follow certain guidelines. This is based on the fact that some companies Fiscal Year's runs from April to March of each year.

My formula needs to follow that if the 2 dates are:

Starts: 01/15/2010
Ends: 01/15/2011

Then for:

2010 Fiscal year: There are 2.5 months (1/15/2010 - 3/31/2010)
2011 Fiscal year: There are 9.5 months (4/1/2010 - 1/15/2011)

if the start and end date were:

Starts: 01/15/2010
Ends: 06/15/2011

Then for:

2010 Fiscal year: There are 2.5 months (1/15/2010 - 3/31/2010)
2011 Fiscal year: There are 12.0 months (4/01/2010 - 3/31/2011)
2012 Fiscal year: There are 2.5 months (4/1/2011 - 6/15/2011)


I have left these detailed instructions in the attached.
Please let me know if you have questions and I can answer.

If you can figure out the formula, you are a genius and I very very much appreciate it!

Thanks you!