The Mayan long count calendar is coming to the end and doomsday theorists believe this signals the end of the world.
However experts insist the end of the Baktun cycle, on 21 December 2012, is in fact no cause for concern, as Mayans actually believed the world would last for millions of years beyond this.
In three days, the 13th Baktun cycle ends, the culmination of a period of almost 400 years. In total, the long count calendar spanned around 5,125 years.
William Saturno, Maya expert, told National Geographic that this is similar to when a car from the 1960s reaches 99,999 miles, its mileage returns to zero.
"We, of course, know that really means a hundred thousand [miles] and not zero. Is [the end of Bak'tun 13] a large period ending? Yes ... Was it predicted to be the end the world? No. That's just us."
Further evidence showing the Maya civilisation did not believe the world would end in 2012 came earlier this year, when notes about the Mayan calendar were discovered in Guatemala.
Archaeologists found writings on the wall of an ancient structure showing how the Mayan calendars work.
Octillions of years
It showed that the Mayans foresaw a huge progression of time - to a mind boggling extent.
Saturno, author of the study published in the journal Science, said: "They were looking at the way these cycles were turning.
"The Maya calendar is going to keep going and keep going for billions, trillions, octillions of years into the future, a huge number that we can't even wrap our heads around.
"The ancient Maya predicted the world would continue, that 7,000 years from now, things would be exactly like this.
"We keep looking for endings. The Maya were looking for a guarantee that nothing would change. It's an entirely different mindset."
NASA is so convinced that the world will not end on Friday that it has released a video explaining why the world "did not end yesterday" for people to watch on 22 December, which can be seen below.