Archive for March 2012

Not so fast, 2012-deniers

Tuesday, March 6, 2012

Don't believe the don't-believe-the-hype hype.

According to a meme being passed around Facebook, Pinterest and other sites in various forms, the historians who calculated the end of the Mayan Long Count calendar as December 21, 2012 forgot to account for leap days. Oops?

This is even being picked up by some news outlets. The International Business Times reported it with the attention-grabbing headline, "Why the end of the world will not happen on December 21, 2012":

There have been about 514 Leap Years since Caesar created it in 45BC. Without the extra day every 4 years, today would be July 28, 2013. Also, the Mayan calendar did not account for leap technically the world should have ended 7 months ago.

Unfortunately for those who want to disprove the doomsayers a few months early, this is completely wrong.

The Mayan calendar makes use of five different periods of time, starting with a single day (k'in). The next period, winal, is 20 k'in. Then, tun is 18 winal (360 days), k'atun is 20 tun, and finally, a b'ak'tun is 20 tun, which makes it 144,000 days.

As the meme suggests, this calendar does not include leap days. In fact, it doesn't have anything to do with solar years at all. At 360 days, a tun is a rough approximation of a solar year, but it's already 5 days off.

The "end of the world", according to doomsayers (and, in Mayan tradition, the end of the current age, or what they considered to be the fourth world), was after the current long-count calendar reached, or in other words, completed the thirteenth b'ak'tun (the digits in the calendar start with zero).

That means that the thirteenth b'ak'tun ends on the 1,872,000th day since the beginning of the calendar. Leap years or not, exactly 1,872,000 days.

So how did we get December 21, 2012?

Since we know that the is equivalent to 1,872,000 days, we need to know exactly what date the Mayan calendar starts on.

According to astrologer John Major Jenkins, an archeologist named J. Eric. S. Thompson determined that corresponded to the Julian date 584283.

Plug this into a handy calculator and you can see that December 21, 2012 is, in fact, 1,872,000 days from Julian date 584283.

Screenshot from Julian Date calculator

Leap days included.

While it would be convenient and quite funny if some anonymous Facebook skeptic realized that historians and chronologists had "forgotten" to include leap days in the conversion from the Mayan calendar to our modern calendar, we can't rule out the end of the world quite yet.