I know! I was supposed to post this yesterday but as you can guess, life got in the way!!

Hello and welcome to one of the most fun days in the calendar year! Yes, that double meaning holiday that brings joy to math nerds and foodies the world over. But guess what? You don’t have to limit your love of π (or pie) to just one day! More on that a little later.

The standard reasoning for choosing today, March 14th, for Pi Day is because the beginning of π is 3.14. But it wasn’t until 1988 that someone thought about it long enough to make the connection and a large-scale celebration was in order. It was California’s Exploratorium physicist Larry Shaw who nabs the honor. But it wasn’t until March 2009 that The House of Representatives agreed to officially designate March 14th as National Pi Day.

This all led Google to do their infamous Doodle and in March of 2014 – it was celebrated as “Pi Month”, allowing the March 14th of 2015 to become “Super Pi Day”! Then to add to the fun, if you use the American style of writing the date then 3/14/15 at 9:26:53 the date and time together represented the first ten digits of π.

According to Wikipedia “Pi Day has been observed in many ways, including eating pie, throwing pies and discussing the significance of the number π, due to a pun based on the words “pi” and “pie” being homophones in English ( /paɪ/), and the coincidental circular shape of many pies. Many pizza and pie restaurants offer discounts, deals, and free products on Pi Day.”

It continues: “The Massachusetts Institute of Technology has often mailed its application decision letters to prospective students for delivery on Pi Day. Starting in 2012, MIT has announced it will post those decisions (privately) online on Pi Day at exactly 6:28 pm, which they have called “Tau Time”, to honor the rival numbers pi and tau equally. In 2015, the regular decisions were put online at 9:26 am, following that year’s “pi minute”,^[26] and in 2020, regular decisions were released at 1:59 pm, making the first six digits of pi.” This is very clever indeed, although I feel stupid that I had to look up what the tau number was.

Here’s what I found out: 2π, also known by the Greek letter tau (𝜏) is a common multiple in mathematics. Some even say it is a more “fundamental” constant than π itself. All of this led to June 28th becoming “Two Pi Day” or “Tau Day” and the “jokingly suggest eating “twice the pie” “. Okay let’s not joke about this. I’m all for eating as much pie as I can handle!!

I love Pi Day because it is also Albert Einstein‘s birthday.

Remember when I said earlier that you can celebrate on other days? Well, here’s a list:

• Pi Approximation Day is (using the Western Style of writing the date) celebrated on July 22nd. This is because the fraction  ²²⁄₇ is accurate to two decimal places.
• I already told you about “Two Pi Day” or “Tau Day” (June 28th)
• And there is a second Pi Approximation Day! This one is celebrated on the 314th day of the year – November 10th

So there you have it – reasons to eat pie (or any other circular food) and all the days (not enough in my opinion) where you can sit back, rub your belly and say “That was so worth it!”