I doubt that the exact hour is exactly the "time". There could be flaws in the math, and our calender may not be in sync with the predicted Mayan date. It could come next week, next year, next decade ... etc ... etc.
So when the exact countdown hour and second arrives, and passe's, don't be so comfortably self reassured, that just because a certain moment in time passed on our clocks, and nothing happened, that now everything is once A-OK again, and is all hunky dorey.
I could name dates and times when we were all happy, complacent and unsuspecting, then suddenly our world was torn apart so many, many, times in a slit second ... Yucatan asteroid, volcanic eruptions and earthquake(s): Mount Vesuvius, Siberia, Mexico, Northridge, Turkey, Iran, Japan, Chernobyl ... etc ... Incidents at Lockerbie, Nairobi, Yemen, Madrid, London, WTC, OK, CT, just to name a but a few.
So when the predicted date passe's without incident, we should all be humbled knowing that anything could happen, at any given time down the road. And we should all reflect, and change our smug thinking, viewpoints, attitudes, and behaviour ... whether you believe in a Creator, creation, or evolution.