Originally Posted by Alcoremortis
I maintain that birthdays are a lie. You only get born once after all. What we really celebrate is the anniversary of our date of birth which is far too wordy for most people.
Which is why so many languages use a different word. Off the top of my head, anniversaire (anniversary) in French or cumpleaņos (completed years?) in Spanish.
This being said, you wouldn't have to say "anniversary of one's date of birth". You can say "birthday anniversary". I fail to see why it would be so much longer and impractical than saying "wedding anniversary" for instance.
EDIT: for that matter, you don't say "wedding day anniversary" so I guess "birth anniversary" would work fine. If it's still too long, try "birthiversary" :P