Larry Shaw, creator of pi Day at the Exploratorium
Pi Day is a holiday commemorating the mathematical constant pi. It is celebrated on MARCH 14 ( 3/14 )
since 3, 1, 4 are the most significant digits of the value pi
Pi approximation day is held on JULY 22 (22/7) since the fraction 22/7 is a common approximation of pi
Larry Shaw created pi day in 1988. The Holiday was taken place at San Francisco Exploratorium, a huge museum for many exhibits to take place.
On Pi Day 2004, Daniel Tammet recited 22.514 digits decimals of pi.
On Pi Day 2009 March 12, Pi day was offficially known as National Pi Day
On Pi Day 2010, Google presented a Google Doodle representing Pi Day, with the word Google laid over images of circles and pi symbols
At 9:26:53 on pi day 2015, the date will be 3/14/15 at 9:26:53, corresponding from 3.141592653
Taken from Wikipedia. I do not own this information