Yellow Pig Day (sometimes called Yellow Pigs Day) is a little-known celebration that has existed since the 1960s. Yellow Pig Day takes place annually on July 17 and is celebrated by mathematicians and others the world over.
Two mathematicians, Michael Spivak and David C. Kelly, were studying mathematics at Princeton University in the early 1960s. As part of their studies, they were given an assignment to study the properties of the number 17. As their studies developed, they started to think of more and more bizarre uses for the number, and their academic minds somehow conceived the idea of a yellow pig with 17 toes, 17 teeth, 17 eyelashes and more. The Yellow Pig was born, and Yellow Pig Day soon followed suit.
Yellow Pig Day has been celebrated on July 17 ever since. According to What The Heck Holidays, mathematicians and academics in colleges and universities celebrate the anniversary with slices of Yellow Pig Cake and Yellow Pig Carols. Yellow Pig Day can be enjoyed simply as a mark of creative thinking, and for mathematicians, a celebration of the curious number 17.
Learning about the number 17
The number 17 has more unique properties than you might have imagined, and academics enjoy finding new startling facts about the number every year. As the Yellow Pigs Web site explains, 'any sequence of fewer than 17 consecutive positive integers contains one number relatively prime to all the other terms.' If that's a bit too mathematically advanced for you, then consider the fact that the ancient Greeks placed 17 columns on the long side of the Parthenon. In any case, try finding new facts surrounding the number 17 as a fun activity to commemorate Yellow Pig Day.
Why a yellow pig?
The idea of the yellow pig is that it simply doesn't conform to any rules, and Yellow Pig Day is about enjoying random thoughts and celebrating the diversity of life. Yellow Pig Day is enjoyed by those who have studied at Hampshire College Summer Studies in Mathematics, a summer program for mathematically inclined high school students, and one of its founders references the yellow pig in several texts. The motto of the day sums it up for those who ask why the founders chose a yellow pig: 'If you have to ask, you just won't understand.'