You're Lucky I'm Around To Write This Stuff For You

Is it bad luck to wish somebody good luck on Friday the 13th?

I'll just sit here under my horseshoe, if it's all the same to you. 

So, it's fairly common in theatre to not wish somebody "good luck."  The convention is to use the phrase "break a leg" in an ironic fashion, in which the performer will be able to acknowledge your wish, but maintain their superstition.  I'm okay with this.  Nobody really knows where this tradition came from.  Some attribute it to a 20th century journalist, others to Elizabethan times where applause was performed by the audience pounding their chairs against the ground.  (If you are enthusiastic with your applause, you would cause the leg of the chair to break.)  

Either way, it's now considered bad luck to wish a performer good luck, and I'm left to wonder whether this applies outside of the theatre as well.  I say it does, because it serves to further my narrative here.  So here we are, on Friday the 13th, the unluckiest of all days.  A day in which everything lucky becomes unlucky.  So, does it work in reverse?  Are things that are normally bad luck now good luck?  Is it still unlucky to wish somebody luck, or should I just go around telling people to break their legs all day.  I'm confused, people!