Calculate birthday and age as if there were 112 days in a year

Hi,

I have Excel 2003,

I'm having trouble with a formula of calculating age from a specific date.

But first I'd like to know a formula to get to a birthdate, using the same 112 days in a year.

I have this:

=DATE(YEAR(O3)/112;MONTH(O3);DAY(O3))

but it shows me back absurd dates, and I need this to be accurate, since I need this cell to get to this, which I'm not sure if it is well built as well:

=INT((TODAY()-N3)/112) &" years and "& DAY(HOJE()-N3) &" days"

O3= Next birthday
N3= Birthdate

Can anyone help?