There's so much hocus pocus in this thread. It's fine as a scary story but if you're actually worried that the world might end then actually find some scientific analysis of the Mayan calendar.
You can spin any story and make it sound truthy by saying it has some science in it, or seems true in some way. But on this matter
there's already a confident academic assessment of the details(url). Any other speculation is just fanciful.
Don't expect me to reply to any challenges to this as I've already given my piece on this issue. If you don't agree with the relevant academics on the issue, then we've got nothing to talk about.