Friday or Tuesday the 13th?!?!?!

So I woke up this morning and realized its FRIDAY 13TH!!!!  I started to get a little worried like "oh boy, what is this day going to bring?"  "What is going to happen??" and more importantly "What is going to go wrong!?!?!?!" 

When I started talking to a good friend of mine.. Carlos! 

PSST!!  He's the one in the middle!!!

 When I reminded Carlos that today was Friday 13th, he responded with "YEY!!  Friday!!  Good Luck, right??'  To which I quickly replied, no its bad luck.  Bad things tend to happen on Friday 13th.  He laughed at me, smiled and said "Amanda, you got it all wrong.  Here Tuesday 13th is bad luck."  Then he started to sing.... 

"En Martes 13, ni te cases, ni te embarques,

Ni de tu casa te apartes"

Which means, "On Tuesday 13th, don't get married, don't start a journey, don't even leave your house."  I know, it sounds a lot cooler in Spanish. :)  But it got me thinking, and I started to do a little research on both Tuesday and Friday 13 and I basically come up with the same results.  No one knows why these days are considered bad, they just know they are.  Evidence started showing up in the 19th and 20th centuries in literature and random references in letters and correspondences writen in the 1900.  The only variable in that in the Western countries, it was alwasy Friday, but in Spain, Latinamerica and Greece the bad luck was always transfered to Tuesday.

So, what gives?!!?!?!  Which day is it, or is it even a day at all??  What do you all think?  Friday or Tuesday??