Yellow Pig Day
July 17 · Level 3 · #1663 of 2238
A joke mathematical holiday built around the number 17 and an imaginary yellow pig. The date is no accident: 17 July is written 7/17 in the American style.
How it is celebrated: mathematicians and students draw yellow pigs, trade puns about 17, split everything into seventeens and snack on something yellow.
Seventeen is a number with character. In 1796, nineteen-year-old Carl Friedrich Gauss showed that a regular 17-sided polygon can be built with just a compass and a straightedge, a result that stunned mathematicians.