Get ready to celebrate National Cheeseburger Day! Did you even know there is a National Cheeseburger Day? That shouldn't be confused with National Hamburger Day. There's one of those, too. National Hamburger Day is in May (during National Hamburger Month), and National Cheeseburger Day is in September. I'm not sure exactly how National Hamburger/Cheeseburger Day is officially celebrated, but it's probably safe to assume that the day is marked by ordering a favorite burger from a favorite restaurant. Where would you order from?