14 March Pi day.

 

Pi Day is an annual celebration that takes place on March 14th (3/14), which represents the first three digits of the mathematical constant pi (π). Pi is the ratio of the circumference of a circle to its diameter, and it is an irrational number, meaning it cannot be expressed as a simple fraction. Pi has an infinite number of decimal places, and its value has been calculated to trillions of digits using computers.

Pi Day is celebrated by math enthusiasts around the world with various activities, such as reciting as many digits of pi as possible, baking and eating pies, and organizing pi-related events and contests. The day is also recognized by educational institutions and scientific organizations as an opportunity to promote math and science education. Pi Day was officially recognized by the U.S. House of Representatives in 2009.