Greeting everyone, and Happy Pi Day! Pi Day is a holiday in honor of the mathematical constant π (pi). Larry Shaw created Pi Day in 1988. Pi Day is observed on March 14 because of the date's representation as 3/14 in month/day date format. This representation adheres to the commonly used approximation of 3.14 for π.What some call "Real Pi Day" will be celebrated on March 14th, 2015 at 9:26:53 AM. These numbers (3/14/15, 9:26:53) correspond with the first 10 digits of pi (3.141592653). But, hey, we shall take what we get and call today Pi Day and deal with it.