Pi Day is celebrated annually on March 14th to commemorate the mathematical constant Pi (Ï), which has been widely studied for over 4,000 years. The first known celebration was in 1988 at San Francisco's Exploratorium and has since become a global phenomenon, with mathematicians using Pi in various fields such as geometry, physics, astronomy, architecture, construction, and mathematics. Piphilology is the practice of memorizing digits of Pi using mnemonic techniques, with notable examples including Rajveer Meena's 70,000 decimal places recited blindfolded. The celebration also includes fun facts about Pi and its connection to Albert Einstein's birthday, as well as various types of pies that people enjoy on this day. InfluxData, a remote-friendly organization, asked their distributed team what their favorite type of pie is, with pecan pie being the most popular choice.