When Is Pi Day 2025 Date. Pi day is a fun little holiday where we can celebrate pi,. The beautiful constant pi (π) is celebrated by mathematicians around the world on national pi day on march 14.

Pi day march 14, friday © shutterstock pi day is an unofficial holiday celebrated around the world on march 14th to honor the mathematical constant π (pi). Unlike some holidays, pi day remains fixed on this date annually, offering enthusiasts a consistent opportunity to indulge in all things mathematical.