Are you triskaidecaphobic?

Forget TGIF -- at least for today. Fear of Friday the 13th turns out to be, essentially, religious.

According to Web sources, Christian tradition has it that Adam and Eve snacked on a particularly potent apple on a Friday. Jesus, of course, is said to have been crucified on a Friday, as well.

As for the number 13, well, there were 13 folks at The Last Supper (12 apostles plus Jesus), and we all know that the 13th guy there -- that'd be Judas -- betrayed the Big Guy.

But most folks say the day's modern fear-mongering origins stem from a papal decision on Oct. 13, 1307. On that Friday, the Pope signed a secret "death warrant" against the Knights Templar, an order that had been Christendom's heroes during the days of the Crusades. Rumor had it these knights were getting a little kooky in their faith, though, so the Pope had them deemed as heretics and had the order's Grand Master, Jacques DeMolay, tortured and crucified.

Which would, when you think about it, make for a very bad day indeed.