It's not just the Mayan calendar that's raising 2012 worries—our own calendar is stoking fear, too. This year, there are three Friday the 13ths, compared to the usual two. That last happened in 2009. What's even stranger is that exactly 13 weeks pass between the first and second occurrence, and between the second and third: The first is today, followed by April 13 and July 13, the News Journal reports. That hasn't happened since 1984, which was, like 2012, a leap year.
The next time this will happen is 2040, says an expert known as Dr. 13. So what is it about the date that people find so scary? Texts throughout history have associated a threat with the date: Jesus, for example, dined with 12 apostles (that's 13 people total) before he died on a Friday. Norse legends say not to eat in groups of 13. The Knights Templar were jailed on a Friday the 13th. But the owner of a pagan bookstore calls the fears a "self-fulfilling prophecy." There is "strong power in people convincing themselves something unlucky will happen," he says. (Read more Friday the 13th stories.)