There was a big shout a while ago about nostradamus predicting the end of the world. I think it was the 8th of August, may have been a bit later. There was a weird scrawl he wrote that had been translated as something like "In the land of the eagle, the destroyer will be born".
The sad thing was that there were people that believed this so strongly they actually gave up on their lives. One guy was interviewed by the press, and stated that on that day he was going to go and sit on a hill in some local picturesque place, and await the end of the world. If you were that guy, at what point do you think that you'd say "oh, ok, guess I was wrong, guess I'll go ask for my job back.".
It turned out the whole thing was a very poor translation, and it went something like "in a village in spain a pair of siamese twins will be born, and a tax collector will come.", those tricky apostrophes.
Also, are we totally sure that we can predict any calendar? I know that the Gregorian Calendar is actually accurate back to 1753, but the whole reason we made it was because we weren't really sure what date it was. Maybe the Mayans did a better job.