Pi Day is an annual US celebration commemorating the mathematical constant (pi). Pi Day is observed on March 14 (or 3/14 in the U.S. month/day date format), since 3, 1, and 4 are the three most significant digits of in the decimal form. In 2009, the United States House of Representatives supported the designation of Pi Day.
In the year 2015, Pi Day will have special significance on 3/14/15 at 9:26:53 a.m. and p.m., with the date and time representing the first 10 digits of .
Pi Approximation Day is observed on July 22 (or 22/7 in the day/month date format), since the fraction 22⁄7 ...