Pi Day

Pi Day or Pie Approximation Day is a day when people around the world celebrate the number pi. They also eat pie to celebrate the pun as both words sound the same. Pi Day is held on March 14.

History

On Pi Day 2004, Daniel Tammet recited 22,514 decimal digits of π.Bank, Alan (March 13, 2009). "Pi Queen holds throne", Daily Pilot. Retrieved 2010-03-14.

On March 14, 2010, Google made a sign celebrating Pi Day, with the word Google laid over images of circles and  nothing else but pi symbols

 Related days 
Tau Day
Tau Day is an unofficial holiday every year since 2010. It is a day to rival, or be against, pi day. Tau day is on June 28, or 06/28 as written in the American date format.

 References 

Category:Mathematical constants
Category:March observances