According to the Gregorian solar calendar, December 21, 2012 c.e., Winter Solstice, coincided with the end of the 13th Bak'tun of the Mayan long count calendar, and supposedly some kind of galactic alignment was going to happen on that day, which pretty much seems to have been much ado about the ordinary (I never put much stock in the event to begin with, it just happened to be an interesting synchronistic aside of sorts; the Winter Solstice itself would’ve worked just fine as far as I was concerned). See Zyzygyz's critique of the event.
So Mayan calendars are elaborate artifacts, but why they would have predicted the course of history itself could never be satisfactorily answered. They were a violent civilization back in the day, hardly paragons of evolution. Which pretty much could be said of all civilizations hitherto, I suppose, so there was nothing outstanding about them except their elaborate calendars (which probably were made for pragmatic agrarian use) and astronomical-mathematical knowledge. Historical correlations originally made vis-à-vis the timewave were guesses. Historical correlations to novelty-dips worked out rather nicely. As Habit decreased steadily and the latter-day flux became gradually more perturbed, it eventually hit the 0-point of the time axis, and that was the end of the story. Originally T. McKenna's correlation date was not December 21, 2012, but it got adjusted later because it seemed to work rather nicely, and somewhat significantly. However, timewave-wise, it should be recalled that the singularity-date was somewhat arbitrarily chosen. Here’s another scenario to consider, just as a matter of synchronistic interest.Now just to reiterate, I am not promoting the idea of looking "without" for signs and portents. Rather, I am suggesting that there "still might be time left" for the timewave to run its course to Zero. For what it's worth. Think of it as a wormhole connecting two portals.
As an aside, regarding the Ten Terrestrial Branches and Twelve Celestial Branches (“Chinese Zodiac”), there is a Sexegenary combination by year, month, day, and even hours which cyclically repeats in “seasonal” time-fractal. The Sexegenary combination of the calendar (Gregorian) year 2013 is 癸巳 (Mizunoto-Mi or Kishi (or Mizunoto-Snake)). Of the Ten Terrestrial Branches, 癸 (Mizunoto) is Water of Yin. Of the Twelve Celestial Branches, Snake is Fire of Yin. So we have a Yin-Yin year in 2013, and the Sexegenary combination gives the classical interpretation of “Water destroying Fire”(水剋火). 癸 is the tenth of the Ten Terrestrial Branches, and it is assigned in the Yin-Yang pentad-phases paradigm to the element of Water. The logogram is associated with the idea of “measuring,” which connotes the phase in which seeds growing in vegetation become large enough to meaure.巳 is ‘Snake’ in the Twelve Celestial Branches. It is the sixth of twelve. In Yin-Yang pentology its element is Fire, and is categorized as Yin. It connotes “maximum entropy” with respect to the growth of vegetation, the state in which no further growth is possible.