You know the stairs in Fawlty Towers, the ones on the landing: they don't seem to have a point other than to make everyone go, comically, up and immediately down again. Well, we have the software equivalent. We receive a term in years (eg: 20) from an external source, we then convert it to months (20 * 12 = 240) and write it to our database. It then sits there, we don't appear to do anything with it, until an enquiry function requests the information. We then convert it to years (240 / 12 = 19.99998) and pass it back. Obviously didn't read the Manuel!