National Pi Day is celebrated annually on March 14th, a date that corresponds with the numerical value of Pi (3.14). This day is marked by math enthusiasts and is often associated with the enjoyment of pie, as the words sound alike. Common customs include hosting pie feasts, where participants share various types of pies, including fruit, chocolate, and meat pies. Activities may also involve baking contests, memorizing the digits of Pi, and visiting science museums that host related events. Additionally, it is a day to share math jokes and celebrate the birthday of Albert Einstein. National Pi Day was first launched by the Exploratorium Museum in San Francisco and has since gained recognition worldwide.