Like many things, the more you look into it, the more confusing it gets. Apparently the official federal title is still Washington’s Birthday (see http://en.wikipedia.org/wiki/Washington’s_Birthday). But since it isn’t Feb. 22, it’s called President’s Day in most places.
If you want to be even more confused, the British Empire didn’t adopt the Gregorian Calendar until 1752, being reluctant to accept anything to do with the pope. (See http://en.wikipedia.org/wiki/Old_Style_and_New_Style_dates).
So the day Washington was born, the calendar on the wall said Feb. 11. Converting this to the current calendar gives Feb. 22. Still, it’s not the exact day I object to—it’s the lack of respect for tradition.