Take a look at your calendar. Tomorrow is Friday the 13th!
You may not take drastic safety precautions every Friday the 13th, but are you totally immune to the superstition? Given the choice, would you get married, start a new job or close on a house on Friday the 13th? Most Americans wouldn't, even though they don't put much stock in the idea. Superstition has a way of creeping up on people when they're in a particularly vulnerable state.How Stuff Works explains why we associate Friday the 13th with bad luck. Link