December 21 marks the end of an age in a 5,125 year-old Mayan calendar, an event that is variously interpreted as the end of days, the start of a new era or just a good excuse for a party.
Thousands of New Age mystics, spiritual adventurers and canny businessmen are converging on ancient ruins in Chichen Itza, southern Mexico and Guatemala to find out what will happen.
A mash-up of academic speculation and existential angst seasoned with elements from several world religions, the 2012 phenomenon has been fueled by Hollywood movies and computer games, and relentlessly disseminated by Internet doom-mongers.
Mass hysteria in a Russian prison, a Chinese man building survival pods for doomsday and UFO lovers seeking refuge with aliens in a French mountain village are just some of the reports that have sprung up in the final countdown to Dec. 21.
US space agency NASA has sought to allay fears of impending catastrophe, noting that "our planet has been getting along just fine for more than 4 billion years, and credible scientists worldwide know of no threat associated with 2012."
Nothing has given the 2012 theories more oxygen in the run-up to the big day than the Internet, noted John Hoopes, a Mayan anthropologist at the University of Kansas.
"This Mayan calendar stuff has been part of hacktivism lore for 40 years, since the beginning, and with every significant change in computer technology, it's gotten another boost," noted John Hoopes, a Mayan anthropologist at the University of Kansas.
Whatever lies in store for the planet, even Mayan academics who have fought to play down the hype surrounding the passing of another 24 hours feel there could still be some surprises.
"I think there may be some mischief on December 21 because the whole world is watching," said Hoopes in Kansas, citing rumors hacktivist group Anonymous was planning a stunt. "It's a very fertile opportunity for a tremendous prank."