Celebrant or celebrator

Which is the correct term to use when refering to someone celebrating his birthday, celebrant or celebrator?

I’m used to using the term “celebrant” but I also hear others saying “celebrator”.

Either can be used (though the other definition of celebrant colours it a bit); a more common term is ‘guest of honor’.

Often we call that person the birthday boy or the birthday girl, even if they are 80 years old.