So confident, in fact, that last night they released a video called "Why the World Didn't End Yesterday," 10 days before the end of the Mayan calendar, which some conspiracy theorists believe signals the end of the world.
According to the video, the Mayan long count calendar—which is more complex than any other calendar ever used—doesn't end on December 21st. It actually rolls over, sort of like a car's odometer. And there's no evidence that the Mayans predicted the end of the world, either.
So rest easy, everybody! December 21st is definitely not going to look like a Roland Emmerich movie.