Written in the USA date format, March 14 is an unofficial celebration for Pi Day derived from the common three-digit approximation for the number π: 3.14. It is usually celebrated at 1:59 PM (in recognition of the six-digit approximation: 3.14159). Some, using a twenty-four-hour clock rather than a twelve hour clock, say that 1:59 PM is actually 13:59 and celebrate it at 1:59 AM or 3:09 PM (15:09) instead. Parties have been held by the mathematics departments of various schools around the world.
This day has been celebrated in a variety of ways. Groups of people, such as math or science based clubs, might gather to consider the role that the number π has played in their lives and imagine the world without π. During such an event, pi celebrants may devise alternative values for π, eat pi (pie), play pi (piñata), drink pi (Piña Colada), eat pi (Pineapple) or watch pi (Pi (film)). The shape of the pie is often square-shaped due to the equation of a round circle = πr2, i.e. “pie are squared.” Enthusiasts also note that the day happens to be Albert Einstein’s birthday. (It is also the birthday of Albert Grimaldi and Albert Lash.) It’s also curious to note that the renowned science and technology university MIT, known as widely for its unconventional, quirky take on math as for its extremely high academic standards and low acceptance rates, often mails out its acceptance letters to be delivered to prospective freshmen on Pi Day.
The “ultimate” pi day occurred on March 14th, 1592, at 6:53 AM and 59 seconds. When written in American-style date format, this is 3/14/1592 6:53.59, which corresponds to the value of pi, rounded to twelve digits: 3.14159265359. However, considering this was well before any kind of standardized world time had been established, and the general public had no concept of π, the occurrence likely went unnoticed.
