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.
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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!