Today is Friday the 13th. Though it comes around more than once a year, few know why Friday the 13 developed such a reputation as an unlucky day. Several explanations exist but one of them thought to be more accurate than others comes from Donald Dossey, founder of the Stress Management Center and Phobia Institute in Asheville, N.C. and noted folklore historian and author of Holiday Folklore, Phobias and Fun. Dossey says Friday the 13's unlucky reputation is rooted in two and ancient, separate bad-luck associations with the number 13 and the day of the week Friday. The two unlucky entities ultimately combined to make one whale of an unlucky day. Dossey traces the fear of 13 to a Norse myth about 12 gods having a dinner party at Valhalla, their heaven. In walked the uninvited 13th guest, the mischievous Loki. Once there, Loki arranged for Hoder, the blind god of darkness, to shoot Balder the Beautiful, the god of joy and gladness, with a mistletoe-tipped arrow. "Balder died and the whole Earth got dark," Dossey said. "The whole Earth mourned. It was a bad, unlucky day and from that moment on, the number 13 has been considered ominous and foreboding.” Have a nice day, ya'll.