Mesoamerican Long Count calendar

December 2012 marks the ending of the current baktun cycle of the Mesoamerican Long Count calendar, which was used in what is now Central America prior to the arrival of Europeans. Though the Long Count was most likely invented by the Olmec,^[10] it has become closely associated with the Maya civilization, whose classic period lasted from 250 to 900 AD.^[11] The classic Maya were literate and theirwriting system has been substantially deciphered, meaning that a corpus of their written and inscribed material has survived from before the European conquest.

The Long Count set its "year zero" at a point in the past marking the end of the previous world and the beginning of the current one, which corresponds to either 11 or 13 August 3114 BC in the Proleptic Gregorian calendar, depending on the formula used.^[12] Unlike the 52-year calendar round still used today among the Maya, the Long Count was linear, rather than cyclical, and kept time roughly in units of 20, so 20 days made a uinal, 18 uinals, or 360 days, made a tun, 20 tuns made a katun, and 20 katuns, or 144,000 days, made up a baktun. So, for example, the Mayan date of 8.3.2.10.15 represents 8 baktuns, 3 katuns, 2 tuns, 10 uinals and 15 days since creation. Many Mayan inscriptions have the count shifting to a higher order after 13 baktuns.^[13][14] Today, the most widely accepted correlations of the end of the thirteenth baktun, or Mayan date 13.0.0.0.0, with the Western calendar are either December 21 or December 23, 2012.^[15]

In 1957, the early Mayanist and astronomer Maud Worcester Makemson wrote that "the completion of a Great Period of 13 baktuns would have been of the utmost significance to the Maya".^[16] The anthropologist Munro S. Edmonson added that "there appears to be a strong likelihood that the eral calendar, like the year calendar, was motivated by a long-range astronomical prediction, one that made a correct solsticial forecast 2,367 years into the future in 355 B.C. [sic]".^[17] In 1966, Michael D. Coe more ambitiously asserted in The Maya that "there is a suggestion ... that Armageddon would overtake the degenerate peoples of the world and all creation on the final day of the thirteenth [baktun]. Thus ... our present universe [would] be annihilated on December 24, AD 2011, [later revised to December 23, 2012]^[a] when the Great Cycle of the Long Count reaches completion."^[18]

Coe's apocalyptic connotations were accepted by other scholars through the early 1990s.^[19] In contrast, later researchers said that, while the end of the 13th baktun would perhaps be a cause for celebration,^[2]it did not mark the end of the calendar.^[20] In their seminal work of 1990, the Maya scholars Linda Schele and David Freidel, who reference Edmonson, argue that the Maya "did not conceive this to be the end of creation, as many have suggested,"^[21] citing Mayan predictions of events to occur after the end of the 13th baktun. Schele and Freidel note that creation date was inscribed at Coba as 13.13.13.13.13.13.13.13.13.13.13.13.13.13.13.13.13.13.13.13.0.0.0.0, with twenty units above the katun. According to Schele and Friedel, these 13s should be treated as 0s, so the Coba number would be read as if it were 0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0, with the units of each column beyond the second (counting from right to left) equal to 20 times those of the previous one (The Maya, due to their cyclical concept of time, also wrote the date of creation, their zero date, as 13.0.0.0.0).^[22] This number represented "the starting point of a huge odometer of time".^[21] Schele and Freidel calculate that the date at which this odometer would run out lies some 4.134105 × 10²⁸ years in the future,^[21] or 3 quintilliontimes the scientifically accepted age of the universe. The issue is complicated further by the fact that many different Maya city-states employed the Long Count in different ways. At Palenque, evidence suggests that the priest timekeepers believed the cycle would end after 20 baktuns, rather than 13. A monument commemorating the ascension of the king Pakal the Great connects his coronation with events as much as 4000 years after, indicating that those scribes did not believe the world would end on 13.0.0.0.0.^[22]