March 14th, 2023
National Pi Day celebrates the mathematical constant number 3.14 ..., which refers to the ratio of the circumference of a circle to its diameter. Pi is an infinite number, and has been calculated to millions of decimal points. It's an opportunity for math enthusiasts to discuss Pi and mathematics in general. Many people also enjoy eating pie on this day, in relation to Pi's homonym "pie."
Restaurants that serve pizza and pie often offer discounts on items today in honor of National Pi Day. Some may feature prices that coordinate to Pi of $3.14.