I was reminded when the presenter on the main morning show on state radio made it into a little pun - martes y trece - Tuesday and the 13th - because Martes y Trece were originally a comic triple act and later a double act. From a quick shufti at the You Tube clips they are not quite Morecambe and Wise, or even Mike and Bernie Winters come to that.
I started to have a look why Spaniards go for Tuesday rather than Friday and why we Anglo Saxons as well as the Hispanics have it in for the 13th. The only consistent Tuesday complaint was that martes, the Spanish word for Tuesday, is derived from Marte or Mars the Greek God of War and so there were links with destruction and what not. Bit thin I thought. The thirteenth has the Last Supper link (13 around the table) and all the Spanish sites talk about how the 13th book of the Apocalipsis (which must be Revelations) introduces the Beast and the Antichrist. There are other even weaker "reasons."
Anyway, either way, be careful out there!