Its a good idea but not a lot of people actually use their real bday. I lied about my age back then to join the older group. After a year of break I returned and spent 5 days guessing. Just made a different account and used it to play games while I kept trying.
that happened with almost all my acounts becuase i forgot about neopets and put in fake info because i would have had to have parents permision and such
wow i thought i was the only one! i put in the right month and day, just changed the year, so it was really easy to guess.