WICHITA, Kan. (KSNW) — Tuesday, March 14, is Pi Day.

You may see it on social media or even at a local business. You probably remember Pi (𝜋) from your school days, that thing about circles and circumferences and it secretly being an impossibly long number.

The date March 14 reads as 3/14 or 3.14 if you prefer. Of course, the first three numbers of Pi are 3.14. So it’s easy to associate the two together.

We’ve known about Pi for a very, very long time. One of the earliest formal civilizations on earth, the Babylonians, were using Pi as early as 2000 BCE., However, their math was a little fuzzy because they thought it was 3.125.

The Egyptians also calculated Pi but thought it was 3.16045. Archimedes got closer with 3.1418.

It wasn’t until 1988 that someone associated the month and day of the week. That was Physicist Larry Shaw.

Shaw was the curator of the Exploratorium, a science museum located at Pier 15 in San Francisco, originally founded by physicist Frank Oppenheimer, brother of the father of the atomic bomb, J. Robert Oppenheimer.

Shaw was on a work retreat when he first thought of associating Pi with March 14. It would be his daughter who recommended also celebrating Einstein with the day since he was born on March 14.

The first Pi Day took place at the Exploratorium on March 14, 1989, with Shaw setting up a table up front with two pies and an urn of tea. By 2009, Congress officially designated March 14 as Pi Day.

Shaw died in 2017, but the holiday he founded continues on and is still celebrated every year at The Exploratorium.

To this day, many people continue to celebrate Pi Day by eating pie themselves.