THE BLOG
12/11/2014 11:17 pm ET Updated Feb 11, 2015

# Why You Need to Do Something Special on Saturday

This coming Saturday is a special day. In fact, it's a once-in-a-lifetime -- 89 years, to be exact -- type of day. News agencies started writing about it last year, Las Vegas is offering special wedding packages for that day, and even Walmart is joining in on the celebration.

So what's all the fuss about? Well, just have a look at Saturday's date:

12/13/14

The next sequential calendar date is January 2, 2103 (01/02/03) -- about 89 years from now. If that's not enough motivation to do something special on Saturday, here are some more (mathematical) reasons.

A sublime and perfect date. Well, actually I'm referring to the "12" in Saturday's 12/13/14 date. 12 is special in many ways, but before I tell you about two particularly noteworthy ones, first let me tell you about perfect numbers.

Perfect numbers equal the sum of their proper divisors -- the factors of the number, excluding the number itself. For example, 6 is a perfect number (the first, actually), since 6=1+2+3. The next perfect number is 28. Now, wouldn't it be interesting if we found some perfection to go along with the uniqueness of Saturday's date? Well you're in luck, because there are 6 divisors of 12: 1,2,3,4,6,12. Perfect! But wait, there's more! Add up those divisors and we get... 28, another perfect number! That's just too much perfection if you ask me. That's why 12 is the first sublime number -- a number whose divisors add up to a perfect number, and which has a perfect number of divisors. To get a sense of just how rare these numbers are, check this out: there are only two known sublime numbers; the second one is

6086555670238378989670371734243169622657830773351885970528324860512791691264

The perfect day for a prime event. If you start counting the week on Monday, then Saturday is the 6th day (perfect!). But even if you don't, perfection is still lurking inside the number 13. As a prime -- a number (greater than 1) whose only divisors are 1 and itself -- 13 is already special. It's not perfect (in the mathematical definition), but hey, you know what, it's the 6th prime number; that's good enough in my book.

I can't leave out another interesting observation: 12 and 13 are related; they are part of the second Pythagorean triple 5^2+12^2=13^2.

No matter how you square it, this Saturday is special. That brings us to 14. Where 12 and 13 were related by an equation involving sums of squares of three numbers, 14 is itself the sum of the first three squares: 14=1^2+2^2+3^2. Pretty amazing isn't it?

I hope I've convinced you that 12/13/14 is a special day. It's perfect, sublime, and might even be the prime day for doing something out of the ordinary. If you especially want to honor the date, shoot for 9:10 a.m. and 11 seconds, or 12:13 p.m. and 14 seconds. Now that's a real once-in-a-lifetime opportunity.