It's a date!

It's a book and, if I'm to judge a book by its cover, it looks to be about the Mayan calendar and the possible end of the world on 12.21.12 - a date also known as December 21, 2012. But

while the top of the back of the book again has 12.21.12 as the date, the text of the first paragraph has the date as December 12, 2012, and

a bit farther down the back, it's again December 12, 2012. On the book's Indigo webpage, the description includes, "foretold to occur on December 21, 2012". The plot thickens! Click an image to enlarge it.