In Spanish-speaking countries, instead of Friday, Tuesday the 13th (martes trece) is considered a day of bad luck.
The Greeks also consider Tuesday (and especially the 13th) to be an unlucky day. Tuesday is considered to be dominated by the influence of Ares (Mars), the god of war. A connection can be seen in the etymology of the name in some European languages (Mardi in French or martes in Spanish). The Fall of Constantinople to the Ottomans happened on Tuesday, May 29, 1453, fact that strengthens the superstition about Tuesday. In addition, in Greek the name of the day is Triti (Τρίτη) meaning literally the third (day of the week), adding weight to the superstition, since bad luck is said to "come in threes".
In Italian popular culture, Friday the 17th (and not the 13th) is considered a day of bad luck. In fact, in Italy, 13 is generally considered a lucky number. However, due to Anglo-Saxon influence, young people consider Friday the 13th to be unlucky as well.
I don't hold much for superstitions, to me it is just another day, but it has inspired some
Anyway, have a little fun with it and try to enjoy your Friday, and if you are a victim of friggatriskaidekaphobia (phobia of Friday the 13th) then maybe one of these great summer cocktails will help calm those nerves!