It's just a number and it's just a day. I was born on the 13th (of Oct.) and it's no biggy. I find it so ridiculous that some buildings pretend they don't have a 13th floor. Umm.. if you're on the floor with a 14 sign.. hate to break it to you
In some asian countries, the 4th is the evil day. Some buildings "don't have" a 4th floor. I guess the word for 4 in Chinese is the same as Death or something like that. Now doesn't that put it into perspective?
In Korea it's believed that if you sleep with a fan on all night, it'll blow your soul away. To the point where some manufacturers give them automatic off settings so you can FALL asleep with it on, but it wont STAY on. (and blow your soul away)
I'm pretty sure you can relax and just watch tv or do some computer stuff as normal.