You may not know this, but Dec. 13, 2014 is a pretty big day. That's 12/13/14 if you were to write it the short way.

Clearly, the month, day and year of that date is written in sequential order, which is always cool. How many time have you seen your friends point out on social media how neat dates like 9/10/11, 10/11/12 and 11/12/13 are?

However, this date isn't noteworthy just because it's a sequence. What's more significant here is that this is the last sequential date we're going to experience this century because a 13th month doesn't exist. You could of course count dates like 1/2/34, but that's kind of cheating, isn't it? 

So lap it up today, baby. Write it on your Facebooks and Twitters and Instagrams. Shout it from the roof tops. Tell everyone you know. You've got to make the day count, because it's likely that you'll never experience something like this again in your lifetime.

Plenty of people have realized this fact and are making sure they take advantage of the day. A lot of people are getting married on this date. In fact, 20,000 U.S. couples plan to get hitched on Dec. 13, 2014, according to a poll conducted by David's Bridal. This is compared to 7,200 during the same weekend last year. One Las Vegas wedding chapel even offered special wedding packages priced at $1,213.14.

The next time there will be a truly sequential date in the Gregorian calendar won't be for 89 years on 01/02/03 or Jan. 2, 2103. So everyone, mark your calendars now with that date and pray that you'll still be alive to see it.

But before you get truly depressed with the passage of time, there are some dates to look forward to coming up this century that are sure to impress any number lovers out there. Smithsonian.com has outlined them all nicely for you, and one of the more notable is Aug. 13, 2021 or 08/13/21. This date shows the Fibonacci Sequence, when each number in a list is the sum of the previous two. In this date, 8 plus 13 equals 21.

The Fibonacci Sequence is best known for providing the basis of the Golden Spiral, which is formed when square tiles are arranged based off of these numbers. The Golden Spiral is found a lot in nature, from seashells to the human ear. Pretty nifty, right?

So see? Just because we technically won't have any more sequential dates this century doesn't mean there aren't still crazy date sequences to look forward to. There's always cool math to find in everyday life.

Image: Dafne Cholet / Flickr