How do people wish people happy birthday on Facebook?

[Anna]

I don't have one, so that's why I'm asking. I was with a guy and it was his birthday, and he was getting things sent to his phone from his Facebook from some people wishing him happy birthday. I was just wondering if that means these people have to have your phone number, or is there like a notification that comes up that says its their birthday and you can click something to wish them happy birthday? How does that work?

[HrannsiB]

Facebook shows each user if one of their friends has a birthday, then the user can choose if he wishes him happy birthday or not.

[Tejas Vyas]

Its just a way of getting notification he have kept his notification on phone so that if any thing notifys him he will get message so if u wish him by sending messages or writing on his wall he will get messages on his phone.