
The Maya calendar is a system of calendars used in pre-Columbian Mesoamerica and in many modern communities in the Guatemalan highlands, Veracruz, Oaxaca and Chiapas, Mexico.
The essentials of the Maya calendar are based upon a system which had been in common use throughout the region, dating back to at least the 5th century BCE. It shares many aspects with calendars employed by other earlier Mesoamerican civilizations, such as the Zapotec and Olmec and contemporary or later ones such as the Mixtec and Aztec calendars.
By the Maya mythological tradition, as documented in Colonial Yucatec accounts and reconstructed from Late Classic and Postclassic inscriptions, the deity Itzamna is frequently credited with bringing the knowledge of the calendar system to the ancestral Maya, along with writing in general and other foundational aspects of Maya culture. Read more

In 2012 some people concluded that the calendar on December 21, 2012 which would coincide with the end of reality as we know it. It was called the Mayan Phenomena and obviously never happened.
The 2012 phenomenon was a range of eschatological beliefs that cataclysmic or transformative events would occur on or around 21 December 2012. This date was regarded as the end-date of a 5,126-year-long cycle in the Mesoamerican Long Count calendar, and festivities took place on 21 December 2012 to commemorate the event in the countries that were part of the Maya civilization (Mexico, Belize, Guatemala, Honduras and El Salvador), with main events at Chichen Itza in Mexico and Tikal in Guatemala.
Various astronomical alignments and numerological formulae were proposed for this date. A New Age interpretation held that the date marked the start of a period during which Earth and its inhabitants would undergo a positive physical or spiritual transformation, and that 21 December 2012 would mark the beginning of a new era.
Others suggested that the date marked the end of the world or a similar catastrophe. Scenarios suggested for the end of the world included the arrival of the next solar maximum; an interaction between Earth and Sagittarius A*, the supermassive black hole at the center of the Milky Way galaxy; the Nibiru cataclysm, in which Earth would collide with a mythical planet called Nibiru; or even the heating of Earth's core.
Scholars from various disciplines quickly dismissed predictions of cataclysmic events as they arose. Mayan scholars stated that no classic Mayan accounts forecast impending doom, and the idea that the Long Count calendar ends in 2012 misrepresented Mayan history and culture.
Astronomers rejected the various proposed doomsday scenarios as pseudoscience, having been refuted by elementary astronomical observations. Read more ...