Hey Poscon,
I created an account back in May of 2018. A friend of mine asked if I wanted to be apart of the Poscon beta (invite three friends). I set my birthday on my profile and gave him the email associated with the account. When he tried to sign me up under my name, it was giving him an error saying my birthdate wasn't set. I tried to look through the website to see if I could resolve the issue but didn't have any luck.
Many Thanks,
Ben H.