LOL No time has been set! In fact you can argue if it's the 21st on our side of the world (because that's where the Mayans are in) or if it's the 21st on the Eastern hemisphere...
Either way, it's just the end of their calendar. They have many calendar endings as do so many other cultures, just as Teri mentioned.
My only fear would be the wackos. But I'm pleasantly surprised to have not heard or seen anyone going off the deep end. Remember a few years ago where the pastor (??) was freaking out saying he calculated the end of the world? People gave up their entire life savings, had their pets put to sleep, and sold everything. And then, whoops...no end of the world.
