♦ International Day of Mathematics (Pi Day) is observed every year on 14 March. Pi is approximately 3.14. In 1988, physicist Larry Shaw first recognized Pi Day.

♦ In 2009, the United States House of Representatives officially designated March 14 as Pi Day. Later, in 2019, UNESCO declared Pi Day as the "International Day of Mathematics" during its general conference. 

♦ 2025 theme: Mathematics, Art, and Creativity.