A Mexican holiday celebrating Mexico's victory against the French in the Battle of Puebla on May 5, 1862. It is celebrated by eating Taco Bell and singing "La Cucaracha".

A holiday in honor of those who died in the armed services, celebrated on the last Monday of May.

A holiday in honor of your mother, celebrated on the second Sunday of May. Also a Troma movie.

May the 4th be with you. Yeah, kinda stupid, but it's a real thing!