"I originally did try to put a birthdate in, and then I got an error saying it was invaild. (When I didn't have a year) I then removed what I had written, then saved the page since I had other edits, and I got an error saying the birthday field was required."From what I remember, once you start editing the date the system won't be happy until you supply one. If you don't edit it, then it will not be required.
Read this thread please.
For birthdays, we can only put in full dates. We can just add month and day without the year. Sometimes, we can't add birthdays for folks who was born in 555 or numbers that go back 1000 such as one of the Hetalia characters, Japan.
Believe, you won't be the last person I moderate wiki and run into this glitch.