Dates and Leap Years

Hi All,
I'm new so be gentle. If I'm in the wrong area, my apologies.

I have a spreadsheet that I am trying to calculate an inmates release date based on days sentenced. There are 2 fields, Field 1 "Years" Field 2 "Months". Staff enters the time sentenced for example: Sentenced 10/3/2011. Length 1 Year, 4 Months.

Most of my rudimentry calculations are working but they are not calculating leap years. I know I need to include the sentenced date in here somewhere, but not sure where. I have attached my file. When you look at the Years to Days and Months to Days, it does not take into account 2012, a leap year.

Any help is appreciated...

Thanks
JEA