Pi Day

Pi Day, observed March 14th, celebrates the mathematical constant π (pi), approximately 3.14159, which represents the ratio of a circle's circumference to its diameter and appears throughout mathematics, physics, and engineering. The date is a direct reference to pi's first three digits, since March 14th can be written as 3/14 in the month/day format commonly used in the United States. The modern celebration is generally credited to physicist Larry Shaw, who organized the first widely recognized Pi Day event at the San Francisco Exploratorium science museum in 1988, complete with a circular parade and fruit pies, a playful pun on the constant's name that has become a lasting feature of the holiday's celebrations. The observance gained further official recognition in 2009, when the U.S. House of Representatives passed a non-binding resolution formally recognizing March 14th as National Pi Day and encouraging schools to use the occasion for math-related activities and education. Pi Day also carries a notable coincidence: it falls on Albert Einstein's birthday, born March 14, 1879, adding another layer of significance for science enthusiasts, and the Massachusetts Institute of Technology has traditionally released its undergraduate admissions decisions on Pi Day as a nod to the school's math and science identity. On Pi Day, people celebrate with math-themed activities, pie-eating and pie-baking, and educational events in schools.