National Yellow Pig Day celebrates the true randomness of the number 17. It's almost as random as seeing a yellow pig! And yet the number plays some pretty important roles in our every day lives. For example, the average loaded school bus weighs 17 tons! Where else do you see the number 17?

July 17th is National Yellow Pig Day, which, surprisingly, has actually very little to with yellow pigs and very much to do with math.

This day originates sometime around the early 1960s. It was inspired by mathematicians Michael Spivak and David Kelly who had dedicated their studies to the randomness of the number 17 and a yellow pig.