Hi
add 730 days, then calcuate
if this month is 1 or 2(i think you have to exclude 29 of february) then you must see if the year is leap or the next year is leap, if one of the two are lead add 1 more day.
if this month is greater than 28 of february then you must see the next 2 year to see if some of then are leap.
If some of then is leap add 1 more day.