a.k.a. December 21, 2012 -or- December 23, 2012 -or- 2012 millenarianism
A cultural meme proposing that transformative and/or cataclysmic events will occur in the year 2012 based on the fact that the Mayan calendar ends on December 21, 2012 (or December 23, 2012 according to some Mayan researchers). Known as the end-date of the Mesoamerican Long Count calendar, which is presented as lasting 5,125 years, various interpretations of assorted legends, scriptures, numerological constructions and prophecies are associated with "2012."
A common new age interpretation of this transition posits that during this time, the planet and its inhabitants will undergo a positive physical or spiritual transformation, and that 2012 will mark the beginning of a totally new era. Conversely some people believe that it marks the beginning of an apocalypse. The 2012 doomsday prediction idea has been disseminated in numerous books and TV documentaries, and has spread around the world as an Internet meme through websites and discussion groups. For descriptions of the various predictions, click on the Wikipedia link below.