This is just the Mayan calendar phenomena. Just because something is old and accurate up until today doesn't meant that it actually predicts the end of the world.
There is just one inscription predicting that a particular god would do something (that's not clearly understood) at that time. Charles Mann suggested that it could be just as plausible to interpret the "investiture" when this god comes to Earth as a kind of party or celebration, and not a cataclysm.
