## What Dates are Mathier than Pi Day?

*March 11, 2012 at 3:14 am* *
7 comments *

While I am grateful that Pi Day gives some much-needed publicity to math, it’s a contrivance like textbook problems about two trains approaching from opposite directions. (Honestly, rather than spend your time determining how long until two trains on the same track collide, why not use that time to inform someone about the imminent collision?) Other than containing the same digits that appear in 3.14, there’s nothing terribly special about 3/14. And it propagates the widely held belief that π is only known to two decimal places.

That said, the cultural significance of Pi Day cannot be overstated. (Or maybe it just was?) Consequently, there are **six cool Pi Day cards at Illuminations** for you to share with friends via Facebook, Twitter, and Pinterest, or download them and include them in an email, on your website, or in a blog post. This one is my favorite:

Recently, there has been a movement to replace π with τ = 2π. (See The Tau Manifesto.) That would suit me just fine, and then we could celebrate Tau Day, which occurs on the more mathematical date 6/28. In addition to 6.28 representing the value of 2π (to two decimal places, anyway), it is also the case that both 6 and 28 are perfect numbers (the sum of their proper factors is equal to the number itself), and this year the value of the month, date and year of 6/28/12 are all even.

Please understand, my disdain for 3/14/12 is not personal. It’s just that other dates this year are, well, *mathier*.

Christmas Eve is one of those mathier dates…

- When written as 12/24/12, all of
*mm*,*dd*and*yy*are even. *mm*+*yy*=*dd*- Each of the digits within the date (1, 2, and 4) are powers of 2.
- The sum of the digits is 1 + 2 + 2 + 4 + 1 + 2 = 12, and 122412 ÷ 12 = 10,201 = 101
^{2}.

…as is the ninth of June…

- The numbers 6, 9, 12 form an arithmetic sequence.
- All three numbers are multiples of 3.
- The month (6) is a perfect number, the date (9) is a square number, and the year (12) is the smallest abundant number.

What do you think is the mathiest date of 2012? And what criteria do you use to determine if a date is mathy?

Entry filed under: Uncategorized. Tags: calendar, dates, Illuminations, pi, pi day, tau, tau day.

1.capnc | March 11, 2012 at 9:15 amIn just three more years, PI day will be a little more interesting: 3/14/15.

Not as interesting as yours, but:

3/4/12 and 2/6/12 form valid product expressions. (As do of course 4/3/12 and 6/2/12, but those seem less interesting).

Not exactly Mathy, but European-style November 21th will be a Palindrome (21/11/12).

2.xander | March 11, 2012 at 11:47 amWhile living in Russia, I got used to writing dates “backwards” (by American standards). Hence I have come to rather like 22/7 (the 22nd of July), and celebrate it as Pi Approximation Day. Even the way it is written is more suggestive than 3/14 could ever hope to be.

xander

3.Squee – It’s Almost Nerdmas « consumedbywanderlust | March 12, 2012 at 9:41 pm[…] What Dates are Mathier than Pi Day? (mathjokes4mathyfolks.wordpress.com) […]

4.Ashley | May 8, 2012 at 9:02 pmI am a college math professor and I LOVE this post – mostly bc my wedding date is 6/9/12! :)

5.venneblock | May 8, 2012 at 9:35 pmCongrats, Ashley! Did you pick that date on purpose, or was it just a wonderful numeric coincidence?

6.Ashley | May 9, 2012 at 10:44 amI picked the date bc of the multiples of 3 (since 3 is my favorite number) :)

7.venneblock | May 10, 2012 at 3:46 pmDon’t you mean it’s the reason that WE picked the date? (Truth be told, I had very little say in the date of my wedding, too!)

You got me to thinkin’. Since 6/9/12 is a Saturday, I’ll assume you wanted to get married on a Saturday. Turns out, there are six Saturdays in 2012 in which all three numbers are multiples of 3:

So in conclusion, I’d like to affirm that you did, indeed, pick the best “multiples of 3” wedding date on this year’s calendar! (And I just

knowthat you and your husband-to-be were sitting at home, anxiously awaiting my approval!)