Is December 21st here already? No? It's tomorrow? Whew! So I still have time to start and finish that novel I've been meaning to write. I do love a deadline.
How time flies while you march towards oblivion.
BOOM! It's all over.
Or, maybe it all will end with the sound of a subtle fart at boring dinner party. Who can say?!
Granted. Revelation is talking about an event from during the time the Roman Empire controlled the Middle East. And Nostradamus was a poet and a doctor who's work future sight is...good for a laugh. And the Mayans, first, didn't really see the fall of their own culture. And, second, don't, even today, think their calendar means remotely what the "experts" think it means.
So, try and reassure anyone that you think might need worrying about that calendars are meant to come to ends, so you'll have to carve another one out of a stone wheel. That, yes, we may well be passing through the galactic center, but it isn't even that interesting to astronomers and astrophysicist (And you know guys like Phil Plaitt are gagging for something interesting to happen.).
It is all stupid. But our culture likes to build this crap up and scare a portion of us. Let's all be the rational counterbalance. Okay?