SUUUUUPER LATE REPLY, but a few months ago, I read this, thought it was a cute idea, and so I went to go check how time-consuming it would be... And then I realized that I don't think any FF characters other than the ones in 7 & 8 actually have official birthdays, so I was thinking it might be kind of weird if it's only the 7 & 8 people who get birthday greetings or whatnot.

And then I proceeded to neglect this comment. D: But yeah, I'm thinking we should maybe not do it unless there are more games where the characters' birthdays are known.