I read man page for etc/shadow field..

on the 8th field, i assume that's the field to change account expire date.

my question is:

What value does the 8th field keep? i assume it's 13514 instead of "Date" value such as 11/10/08.

on the man page, it said: " expire value = 13514 = jan 1, 2007"

How do you get 13514 ?

Is there any calculation involves?