Pi Day was first celebrated in 1988 and planned by Larry Shaw. The numerals 3, 1, and 4 are the most important numbers in the Pi formula, which is a standard ratio for any circle's circumference to its diameter. The number 3.14 continues indefinitely, but the majority of people simply use the first three numbers.
On March 12, 2009, the U.S. House of Representatives passed a non-binding resolution (HRES 224),[2] recognizing March 14, 2009 as National Pi Day