Tags: Holiday.
Pi Day is an annual American celebration commemorating the mathematical constant π (pi). Pi Day is observed on March 14 (or 3/14 in the month/day date format) since 3 1 and 4 are the first three significant digits of π in decimal form. In 2009 the United States House of Representatives supported the designation of Pi Day.Pi Approximation Day is observed on July 22 (or 22/7 in the day/month date format) since the fraction 22⁄7 is a common approximation of π.
