One thing, however, became clear to many by Friday afternoon: The world had not ended.
John Hoopes, an assistant professor of anthropology at the University of Kansas, was at the ruins, using the opportunity to talk about how myths are created.
"You don't have to go to the far corners of the earth to look for exotic things, you've got them right here," he noted.
End-of-the-world paranoia, however, has spread globally despite the insistence of archeologists and the Maya themselves that the date meant no such thing.
Dozens of schools in Michigan canceled classes this week amid rumors of violence tied to the date. In France, people expecting doomsday were looking expectantly to a mountain in the Pyrenees where they believe a hidden spaceship was waiting to spirit them away. And in China, government authorities were cracking down on a fringe Christian group spreading rumors about the world's end, while preaching that Jesus had reappeared as a woman in central China.
Gabriel Romero, a Los Angeles-based spiritualist who uses crystal skulls in his ceremonies, had no such illusions as he greeted the dawn at Chichen Itza.
"We'll still have to pay taxes next year," he said.
As if to put the final nail in the coffin of such rumors, Bob McMillan of the University of Arizona's Lunar and Planetary Laboratory confirmed Friday that no large asteroids are predicted to hit anytime soon.
And Bill Leith, a senior science adviser at the U.S. Geological Survey, noted that as far as quakes, tsunamis and solar storms for the rest of the day, "we don't have any evidence that anything is imminent."
Still, there were some who wouldn't truly feel safe until the sun sets Friday over the pyramids in the Yucatan peninsula, the heartland of the Maya.
Mexico's best-known seer, Antonio Vazquez Alba, known as "El Brujo Mayor," said he had received emails with rumors that a mass suicide might be planned in Argentina. He said he was sure that human nature represented the only threat Friday.
"Nature isn't going to do us any harm, but we can do damage to ourselves," he said.
Authorities worried about overcrowding and possible stampedes during celebrations Friday at Mayan sites such as Chichen Itza and Uxmal, both about 1 1/2 hours from Merida, the Yucatan state capital. Special police and guard details were assigned to the pyramids.
Yucatan Gov. Rolando Zapata said he for one felt the growing good vibes, and not just because his state was raking in loads of revenue from the thousands of celebrants flooding in.
"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.
Associated Press writers Romina Ruiz-Goiriena in Iximche, Guatemala; Bradley Brooks in Sao Paulo; Carlos Valdez in Isla del Sol, Bolivia; and Florent Bajrami in Bugarach, France, contributed to this report.