When Is Pi Day?
Pi Day is observed on March 14.
What Is Pi Day?
Get ready for a flashback to middle school math class.
First and foremost, Pi Day is a celebration of the mathematical constant, π (pi), or 3.14159265359. As you can see, the date is literally the first three major numbers, when you write March 14 in a numerical format, like 3/14. That's right: Pi Day is about math, but thankfully, someone made it fun with pies. Best of all, a lot of people tend to celebrate the occasion with pizza, too, which arguably makes Pi Day better than National Pie Day.
The annual celebration of numbers and food is relatively new. Larry Shaw is credited with holding the earliest known large-scale celebration of Pi Day in 1988 at the San Francisco Exploratorium, where he worked as a physicist. The public joined museum staff for a march around the building's circular spaces, then gathered to eat a bunch of pies, according to a report by Newsweek. The U.S. House of Representatives voted to officially recognize Pi Day in 2009, although then-Congressman and current Vice President Mike Pence and nine other Republicans voted against the measure. Today, Shaw is known as the Prince of Pi, largely thanks to his brilliant idea to make math more fun with dessert.