By now, most people know the date of the end of the world,according to the Mayan calendar — Dec. 21, 2012. But, um, does anyone know what exactly is supposed to happen — or when?

"I thought that, at midnight, the Earth would lose gravity and we'd all be sucked into space," one colleague said.

"So what time is the#apocalypse?" @spellingwitch wrote on Twitter. "I mean, is it midnight local time? Midday? Or close of business? I'd like to plan my last activities."

To find comfort in the answers, we turn to the Internet. Here's what to expect when you're expecting the end:

The predictions call for major catastrophes – plural –that may include earthquakes, environmental destruction, social chaos, the Earth undergoing a magnetic field shift and reversing the polarity of the planet, and an asteroid or comet colliding with Earth, according to www.2012endofdays.org.

Of course, we've had over a thousand years to prepare for the end, but apparently the details are squishy.

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Astrophysicist Jocelyn Bell Burnell said the most likely disaster is a black comet striking Earth, the Daily Mail reports. Apparently, the difference between a black comet and your run-of-the-mill comet is that black comets have less ice and snow and more dust, which makes them harder to spot in space. The collision wouldn't necessarily cause the Earth to explode, but rather would create a giant dustball in the atmosphere that could kill billions of people slowly and destroy crops.

Other predictions include a super volcano, an undersea landslide and a collision with a rogue planet called Nibiru, the Daily Mail says.

One footnote from the author on 2012endofdays.org tempers that great-balls-of-fire forecast: "Another possibility is that each cycle marks an era of great change or human innovation, not destruction."

Wow, so that could be like the dominance of mobile Internet or Anywhere TV, right?

Eh, whatever. Great balls of fire and planning for what we'll do on that last day and in those final minutes is far more fun.

OK, so now back to @spellingwitch's question: What time is the end?

There are two possible times: One is midnight (tonight/the beginning of Dec. 21) and the second is the winter solstice, which would be 11:11 a.m. on Dec. 21, so, go ahead and high five when the clock strikes midnight but just know this apocalypse is give or take 11 hours.

Some crafty tweeters point out that if the world were ending at midnight, then it would have already happened in New Zealand. Hey, I never thought of that – will the end roll with the time zones? Some even craftier tweeters suggest that the Mayans were on Central Time, not New Zealand time. In fact, that Mayan calendar is apparently tied to Universal Time (GMT). So, sorry, California, your apocalypse is coming early this year! (Check www.worldtimezone.com for your own conversion)

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So, how is everyone spending their final day?

"It appears Pittsburghers will spend our final 24 hours on earth dealing with a winter storm. Well-played, universe #Apocalypse," Ashlie Hardaway wrote on Twitter.

"The world ends tomorrow. Hit the gym, eat well and leave a good looking corpse. #apocalypse," Francesca Fox tweeted.

Model Niki Ghazian told the New York Post she hopes to have some end-of-the-world sex Thursday night, echoing the sentiments of countless others who have decided to skip the bunker and head straight to the party.

"I will be looking for an end-of-the-world hookup," New York bartender Dennis Cintron told the Post. "If you're going to go out, go out with a bang!"

The New Yorker offers an end-of-the-world playlist, which includes Vic Chestnutt's "It's the End of the World as We Know It (And I Feel Fine)" as well as Al Green's "The End Is Near."

Of course, not everyone is convinced this is the end.

@GirlProblems raises a good point on Twitter, uploading an image that said: "Calm down. If the Mayans were good at predicting the future,there would still be Mayans."

Touche, @GirlProblems.

Josh Gates, host of "Destination Truth" on the SyFy channel (a sister network of CNBC), summed it up this way: "Perfect afternoon in Progreso, Mexico. Your move, #apocalypse."

So, if this is it – it was nice knowing you. We had some good times. If we make it to noon tomorrow, well, I'll always have my Mayan apocalypse commemorative coin that I bought on the Internet for 88 cents (plus shipping) to remember – fondly, of course – that time we survived the end together.

And then, while we're toasting our survival and the new year, we can figure out what to freak out about nex—

Holy great balls of fire, did you know next year is the year 13? Eeeeeeeeeeek!