What cracks me up about Doomsday folks, is that they're just as ready to re-schedule their Doomsday as they are to believe so strongly about it in the first place.
"Hmm... we must have miscalculated something (because lord knows the only way to explain us being wrong is to introduce some mind boggling mathematics formula that only we're intelligent enough to understand - and surly we can be forgiving for making the slightest of errors in it - 'cause it's so gosh darn complicated, that it would give Einstein autism just to look at...)"
"So, how's next year sound?"
"Yeah, my calendar is open."
"Good, let's do it then."
"Sounds like a plan."
...
* in unison - "OH MY GOD! THE WORLD IS GOING TO END IN JUST 365 DAYS!!!!!!!!!!"