Think all those are funny? How about a half-birthday? Many also commemorate the day exactly six months before their real birthday! It's often done if their real birthdays happen to fall on very popular holidays such as Christmas or New Year's Eve; by celebrating a half-birthday in such cases, these people can celebrate with coworkers or fellow classmates since most schools and businesses are closed during those holidays. After all, wouldn't you hate it if your birthday was December 25 and you got shortchanged on presents but have no way of proving it?