Tomorrow is Friday the 13th. While the dreaded combination evokes feelings of unease even among non-believers, for the superstitious, it is the unluckiest day of the year. Their intense fear, dubbed friggatriskaidekaphobia, leads to symptoms that range from mild anxiety to a nagging suspicion of bad luck to full-blown panic attacks. While some of the trepidation can be attributed to the namesake movie series, the day’s ill-fated reputation was well-established long before Jason Voorhees, the film’s hockey-masked villain, first appeared on the big screen in 1980.