Not that I believe in this stuff, but it appeals to my nitpicking fanboy side to ask when the proper time to celebrate the end of the world will be.
Did the Mayans celebrate the end of day at midnight? Sunset? Sunrise? Did they have a concept of time zones? Mysteries of the Unknown wants to know!
The apocalypse is supposed to happen at the moment of the Winter Solstice. 11.11am UTC.
According to modern ‘experts’ anyway.
Here’s a countdown clock. You have just over 4 hours left. 
I can’t wait! I can’t wait! I can’t WAIT!
Damn, does that mean I’ll miss lunch?
Of course, there’s some uncertainty about the dates of the Mayan long count calendar. See: Does the Mayan calendar predict the end of the world in 2012? - The Straight Dope … so, if the world doesn’t end today, it’s still possible that it will end on Dec 23. If not, well, I guess you can wait for the next 5,100 or so years for the next time the long count calendar cycles round.
Note that the Mayans themselves…
(A) Did not say that the end of the Long Count meant the end of the world. It’s the same as the Gregorian calender rolling over to the next millenium.
(B) Never actually experienced any change of the Long Count, because they weren’t remotely old enough as a civilization.
© Weren’t all that hot at foretelling the future.
It happened!! Didn’t you notice? Of course, the world was instantly reconstituted with all the same people and all the same problems. Couldn’t they at least have gotten rid of the fiscal cliff?
Until the mid 19th century, nobody had a concept of time zones. Everyone used local mean time.
And tomorrow it will come to an end on December 23.
And the day after that, it will come to an end on December 24.
And the day after that, it will be Christmas, and you’ll stop wishing for these ads to come to an end.
This is a really picayune correction, but in most cases people used apparent (or true) solar time, which has days of slightly variable length. Local mean time uses the average (or mean) length of exactly 24 hours. I was surprised to see, though, that according to Wikipedia the ancient Babylonians knew the equation of time for calculating local mean time, though apparently until the modern era it was used “backwards” to adjust mechanical clocks to match apparent solar time. I have no idea whether the ancient Mayans knew about the difference between apparent solar time and mean solar time.