The social network Imgur posted photos of clocks turning midnight in the Asia-Pacific region with messages such as: "The world has not ended. Sincerely, New Zealand."
In Merida, the celebration of the cosmic dawn began with a fumbling of the sacred fire meant to honour the calendar's conclusion.
Gabriel Lemus, the white-haired guardian of the flame, burned his finger on the kindling and later had to scoop up a burning log that was knocked out of the ceremonial brazier onto the wooden stage.
Still, the white-clad Lemus was convinced that it was a good start, as he was joined by about 1,000 other shamans, seers, stargazers, crystal enthusiasts, yogis, sufis and swamis at the convention centre about an hour and a half from the Mayan ruins at Chichen Itza.
"It is a cosmic dawn," said Lemus. "We will recover the ability to communicate telepathically and levitate objects ... like our ancestors did."
Celebrants later held their arms in the air in a salute to the Thursday morning sun.
"The galactic bridge has been established," announced spiritual leader Alberto Arribalzaga, who led the ceremony. "At this moment, spirals of light are entering the centre of your head ... Generating powerful vortexes that cover the planet."
Few here believe the world will end on Friday; the summit is scheduled to run through Sunday. Instead, participants say, they are here to celebrate the birth of a new age.
A Mexican Indian seer who calls himself Ac Tah, and who has travelled around Mexico erecting small pyramids he calls "neurological circuits," said he holds high hopes for December 21.
"We are preparing ourselves to receive a huge magnetic field straight from the centre of the galaxy," he said.
Terry Kvasnik, 32, a stunt man and acrobat from Manchester, England, said his motto for the day is "Be in love, don't be in fear." While he didn't know exactly which ceremony he'll attend on Friday, he guaranteed with a smile, "I'm going to be in the happiest place I can."
If anything, the summit was a blissed-out focal point for the yoga-and-chakra set, with participants wearing T-shirts that read "Shiva Rules," or getting their auras photographed with "chi" light. In the exhibition hall people had their pick of crystal vendors and faith healers.
They could also learn the art of healing drumming with a Mexican Otomi Indian master who calls himself Dabadi Thaayroyadi and says his slender, hand-held, plate-sized drums are made with prayers embedded into them. He said the drums emit "an intelligent energy" that can heal emotional, physical and social ailments.
During the opening ceremony participants chanted mantras to the blazing Yucatan sun, which quickly burned the fair-skinned crowd.
Violeta Simarro, a secretary from Perpignan, France, took shelter under a nearby awning and noted that the new age won't necessarily be all peaches and cream.
"It will be a little difficult at first, because the world will need a complete 'nettoyage' (cleaning), because there are so many bad things," she said.
Not all seers endorse the celebration.
Mexico's self-styled "brujo mayor," or chief soothsayer, Antonio Vazquez Alba, warned followers to stay away from all gatherings on December 21, saying, "We have to beware of mass psychosis" that could lead to stampedes or "mass suicides, of the kind we've seen before".
"If you get 1,000 people in one spot and somebody yells 'Fire!' watch out," Vazquez Alba said. "The best thing is to stay at home, at work, in school, and at some point do a relaxation exercise."
Others see the summit as a model for the coming age.
Participants from Asian, North American, South American and European shamanistic traditions amiably mingled with the Mexican hosts.
"This is the beginning of a change in priorities and perceptions. We are all one," said Esther Romo, a Mexico City businesswoman who works in art promotion and galleries. "No limits, no boundaries, no nationalities, just fusion."
Still, organisers of Yucatan's broader Mayan Culture Festival saw the need to answer the now-debunked idea that the Mayas, who invented an amazingly accurate calendar almost 2,000 years ago, had somehow predicted the end of the world. The Mayas measured time in 394-year periods known as baktuns. Anthropologists believe the 13th baktun ends around December 21, and 13 is considered a sacred number for the Maya. But archaeologists have uncovered Mayan glyphs that refer to dates far, far in the future, long beyond December 21.
Yucatan Gov. Rolando Zapata, whose state is home to Mexico's largest Maya population and has benefited from a boom in tourism, said he too felt the good vibes.
"We believe that the beginning of a new baktun means the beginning of a new era, and we're receiving it with great optimism," Zapata said.
He confirmed that thousands of tourists and spiritualists are expected for Friday's once-in 5,125-year event.
"We have information that all the flights to the city are completely full," Zapata said.
The Yucatan state government even invited a scientist to talk about the work of Large Hadron Collider in Switzerland, to debunk the idea it could produce world-ending rogue particles, a concept popularized by author Steve Alten in his recent book "Phobos, Mayan Fear."
Alten suggests the rogue particles - "tiny black holes" - could unleash earthquakes that might cause a huge tsunami, but acknowledges that linking such events to December 21 "is author's license".
"It's science fiction theory, I'm a science fiction writer," he told The Associated Press.
The European Organization for Nuclear Research, however, has listed a number of odd subatomic phenomena - "magnetic monopoles," "Vacuum bubbles" and "strangelets" - that could play a role in the next apocalypse scare.
All of it amused Mexico City-based tourist Deyanira de Alvarez as she snapped a photo of the countdown clock mounted in the Merida international airport showing just over two days left to "the galactic alignment".
"My grandmother says that people have been talking about this (the world ending) ever since she was a little girl," De Alvarez said, "and look, grandma is still here".
- AP
