The ancient people measured time in cycles called "baktuns" of 394 years each, and the winter solstice coming Friday marks the end of the 13th baktun. Some who study the calendar say the date for the end of the period is not Friday, but Sunday.
The Mayan calendar is based on the position of the heavenly bodies -- the sun, the moon and the stars -- and was meant to tell the Mayan people about agricultural and economic trends, said archeologist Alfredo Barrera.
NASA is also weighing in on the matter, with a post on its website declaring that the world will not end on Friday.
"It will be another winter solstice," NASA said. "The claims behind the end of the world quickly unravel when pinned down to the 2012 timeline."
As of Thursday afternoon in the eastern United States -- already Friday across Asia -- the space agency said it had detected "nothing unusual" and that it anticipated a normal couple of days ahead.
The hubbub about a calamity occurring comes from a Mayan stone carving called monument 6, made in 700 A.D., which predicts a major event at the end of this baktun, Barrera said. But half of the broken tablet is missing, so one may only speculate on what the complete message may be.
Whatever it is, it's not about the end of the world, he said.
"We don't have a prophecy or inscription related to the finish of the world. It just mentioned a deity."
Barrera said he believes the hullabaloo about the end of the world has been whipped up by online speculation -- and he finds it a bit ignorant.
In Merida, Mayan priest Valerio Canche conducts an ancient ritual to honor the dead in light of the upcoming end of the 13th baktun.
"It is considered the closure of the great cycle of Mayan time," he said. "But, of course, the cycle (14th baktun) begins the following day. For the Mayans, it's not the end of the world."
If you're reading this on Thursday, keep in mind that it's already Friday in New Zealand, and it's still on the map. If it's Friday, a look out the window may be reassuring.
If it's Saturday, and no major calamity has occurred, then relax and go celebrate the beginning of the 14th baktun with the Mayans.