That is a good question. The short answer is : no one says, and you will never hear « Quand est ton anniversaire ? », therefore, you should not use it, period.
But indeed, this is a very good question, and a tricky one. Because you surely can say « Où est ton livre ? » I'd love to say that I have the answer, but I don't. So far. ;)
I hope I'll come back with it soon.