The Maya 2012 doomsday prediction
The date 21 December 2012 drew predictions of cataclysm, because a cycle of the Maya Long Count calendar ended then. NASA said the idea of a Maya prophecy of the world's end rested on a misconception.
Wikipedia describes the 2012 phenomenon as a set of beliefs in catastrophic or transforming events around 21 December 2012. The date was regarded as the end of a 5,126-year cycle in the Mesoamerican Long Count calendar. ScienceNordic gives the arithmetic: the Maya count most likely began in 3114 BC, on 11 August. A a baktun of 144,000 days, just over 394 years, brings the count to 21 December 2012.
Festivities marked the day in Mexico, Belize, Guatemala, Honduras and El Salvador, lands of the Maya civilization. Wikipedia names Chichén Itzá and Tikal as the main sites.
The Cape Times, reporting from Cape Town on Friday 21 December 2012, wrote that NASA had been flooded with questions about the supposed end of the world. The agency was confident enough that nothing would happen that it had already put an article online for the next day. The paper said that article, by Dr Tony Phillips of Science@NASA, held that talk of an old Maya prophecy ending the world that day was mistaken "from the very beginning". The world carried on after 21 December 2012.
"The 2012 phenomenon was a range of eschatological beliefs that cataclysmic or transformative events would occur on or around 21 December 2012.[1][2][3] This date was regarded as the end-date of a 5,126-year-long cycle in the Mesoamerican Long Count calendar,[4] 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 Chichén Itzá in Mexico and Tikal in Guatemala.[5][6][7]"
- Why the world didn't come to an end, IOL / Cape Times (2012)
- 21 December 2012: time for another doomsday, ScienceNordic (2012)