Calendar ends in 2012 - Oh Noes!!

By its linear nature, the Long Count was capable of being extended to refer to any date far into the future (or past).

Misinterpretation of the Mesoamerican Long Count calendar is the basis for a New Age belief that a cataclysm will take place on December 21, 2012. December 20, 2012 is simply the last day of the 13th b'ak'tun, which began September 18, 1618 (1,728,000 days from the beginning of the calendar).

The completion of significant calendar cycles ("period endings"), such as a k'atun-cycle, were often marked by the erection and dedication of specific monuments (mostly stela inscriptions, but sometimes twin-pyramid complexes such as those in Tikal and Yaxha), commemorating the completion, accompanied by dedicatory ceremonies.

"Timewave zero" is a numerological formula that purports to calculate the ebb and flow of "novelty", defined as increase in the universe's interconnectedness, or organised complexity,[58] over time. According to Terence McKenna, who conceived the idea over several years in the early-mid 1970s while using psilocybin mushrooms and DMT, the universe has a teleological attractor at the end of time that increases interconnectedness, eventually reaching a singularity of infinite complexity in 2012, at which point anything and everything imaginable will occur instantaneously.[58]McKenna expressed "novelty" in a computer program, which purportedly produces a waveform known as timewave zero or the timewave. Based on McKenna's interpretation of the King Wen sequence of the I Ching,[59] the graph appears to show great periods of novelty corresponding with major shifts in humanity's biological and cultural evolution. He believed the events of any given time are recursively related to the events of other times, and chose the atomic bombing of Hiroshima as the basis for calculating his end date in November 2012. When he later discovered this date's proximity to the end of the 13th baktun on the Maya calendar, he revised his hypothesis so that the two dates matched.[60]The first edition of The Invisible Landscape refers to 2012 (as the year, not a specific day) only twice. McKenna originally considered it an incidental observation that his and Jos Argelles dates matched, a sign of the end date "being programmed into our unconscious". It was only in 1983, with the publication of Sharer's revised table of date correlations in the 4th edition of Morley's The Ancient Maya, that each became convinced that December 21, 2012 had significant meaning. McKenna subsequently peppered this specific date throughout the second, 1993 edition of The Invisible Landscape.[32]

Somehow unable to predict the end of their entire world

But he confidently stated in the letter that the Bible proved the world would end in 2060, adding: "It may end later, but I see no reason for its ending sooner."Continuing in a decidedly sniffy tone, he wrote: "This I mention not to assert when the time of the end shall be, but to put a stop to the rash conjectures of fanciful men who are frequently predicting the time of the end, and by doing so bring the sacred prophesies into discredit as often as their predictions fail."