Among their other accomplishments, the ancient Mayas invented a calendar of remarkable accuracy and complexity.
The Maya calendar was adopted by the other Mesoamerican nations, such as the Aztecs and the Toltec, which used the mechanics of the calendar unaltered but changed the names of the days of the week and the months. The Maya calendar uses three different dating systems in parallel, the Long Count, the Tzolkin (divine calendar), and theHaab (civil calendar). Of these, only the Haab has a direct relationship to the length of the year. They also have calenders which track the planets, with Venus (apparently associated with war) in particular playing an important role.
The solar year was established using straight necked vases or similar methods to show when the sun was directly overhead, establishing the start of the annual maize sowing season. Otherwise there is little to indicate the Mayan calender acknowledged either the solstice or equinox (although the layout of some sites does, and the positioning of buildings also reflects stellar constellations), it is a fact that the end of the fifth era falls on the winter solstice of the 21 December 2012. An era lasts just over 5,125 solar years , each era resulting in a change, and every 5 eras a major change. The era passing saw the creation of humankind, there is no indication as to what comes next. The 25,620 year cycle of the Long Count is close to the 25,800 year cycle of precession wherby the wobble in the earth's axis as it spins causes the sun to seem to move backwards through the zodiac. The earth is currently crossing the galatic plane, although the winter solstice was calculated to have so aligned in 1998/99.
Despite its current topicality there is only one reference so far discovered which mentions 21 December 2012. This inscription, known as Tortugero Monument 6, just north of the Guatemalan Mexican border does refer to b'ak'tun 13. A rough transalation, by David Stuart, bearing in mind it is partially destroyed and not completely understood is as follows -
"Tzuhtz-(a)j-oom u(y)-uxlajuun pik
(ta) Chan Ajaw ux(-te’) Uniiw.
Y-em(al)?? Bolon Yookte’ K’uh ta ?.
“The Thirteenth ‘Bak’tun” will be finished
(on) Four Ajaw, the Third of Uniiw (K’ank’in).
? will occur.
(It will be) the descent(??) of the Nine Support? God(s) to the ?.”
The Nine Gods are, rather ominously, the Gods of the Underworld but it is the term following "uht-oom" which is the main puzzle, and largely effaced. The “descent” reference is highly tentative, too. The enigmatic deity Bolon Yookte’ K’uh has been known for some time from many sources, and I suspect that he (or they) has some tangential relationship to the Principal Bird Deity, as well as war associations. Interestingly, he is a protagonist in the deep time mythology of Palenque, as recorded on Palenque’s Temple XIV tablet. A long-lasting character who’s still around somewhere waiting."
Bolon Yokte, apart from his association with Quetzalcoatl, appears to be a God or Gods of war, conflict and the underworld. Among many superficially inexplicable similarities in symbolism between the old world and the new, assuming there was no cultural cross-fertilisation, was the image of a man in the mouth of a serpent. Said to be indicative of dreams or hallucinations in meso-america, it symbolised initiation into the esoteric in Europe. Some have suggested that Shamanism, and even the feathered serpent, reminiscent of the Chinese dragon, owe their origins to the Asiatic ancestors who walked from Siberia before the Baring Straits flooded some 15,000 years ago. This practice, still observed today in Guatemala and elsewhere, was also well known in early renaissance Europe. Dr John Dee, Queen Elizabeth's court astrologer, relied heavily on Edward Kelley, who subsquently made and lost a title and a fortune in Bohemia in the service of the Holy Roman Emperor Rudolf the second, to provide contact with the spirit world, or angels as Chrstians called them, in a process known as "skrying". Neither Dee nor Kelley seemed entirely sure how genuine the communication was, but persisted nonetheless until a complicated matrimonial cross-over caused the relationship to terminate.