National Pi Day 2024. Founded in 1988 at the exploratorium, pi (π) day has become an international holiday, celebrated live and online all around the world. It's all about celebrating the number pi, which is 3.14.
National pi day is celebrated annually on march 14th (3/14), commemorating the mathematical constant π (pi), which represents the ratio of a circle’s circumference to its diameter. After centuries of using various shapes to try to get the correct number for pi (π), greek.