December 21, 2012 is the date the Mayans predicted that the world will end. The prediction, however, doesn't confirm that this event will actually happen. Many groups have attempted to predict the end of the world and have failed at doing so. The truth is, no one knows when the world will end. The quest to figure it out is a way of humankind trying to have more control over the natural process of time, but there is no real way to do this.
No one should worry that the world will end on December 21, 2012. No evidence remotely suggests this. Some people have interpreted the calendar of a long dead civilization to predict this, but that interpretation is extremely disputed, and even if it were not, there is no reason to believe that Mayans would somehow have a supernatural power to predict the future.
There's no scientific data that shows any indication that the world will end anytime soon. It's just a hoax just like all those doomsday hoaxes in the year 2000. No scientist has come out to say that we are in any danger whatsoever. We cannot count on the world ending just based on the fact of the Mayan calendar being finished.
Whether there is a final curtain or not on the 21st, there's nothing any of us can do to stop it. Granted, not seeing December 22nd is a bummer, but actively worrying about a hypothetical end will only leech joy out of life. A life which doesn't have much longer to go, if the Mayans are to be believed. Instead of fretting, everyone should go enjoy a sunset, or walk hand-in-hand with a friend, or finally take the time to stop and smell the roses.