There have been about 514 Leap Years since Caesar created it in 45 BC. Without the extra day every 4 years, March 9th would have been July 28, 2013.
Also, the Mayan calendar did not account for Leap Year.
Also, the Mayan calendar did not account for Leap Year.
That means, technically, that the world should have ended 7 months ago.
So now we can stop worrying about the end of the world and get on with our lives.
Whew...what a load off!