It has something to do with the profile fields update, as for which one I have no clue as I didn't dig that far into CF code. I'm sure there's a trigger that happens when a user saves their profile information and the CF rechecks the date of birth for changes. There also as to be another detection for untouched DoB but the user AGES to the correct age to unlock more CF settings, as for where to begin looking for that.... no clue.

The strings that tie the CF feature together is that of a spiderweb, a very maze-like spiderweb.