According to Wikipedia some people are so paralyzed by fear that they avoid their normal routines in doing business, taking flights or even getting out of bed. In the past, "it's been estimaed that USD800 or 900 million is lost in business on this day. Despite this, Airlines dont suffer from any noticeable drop in travel on those Fridays' .
As we can see there is a Movie also titled as Friday, The 13th. I wanted to watch like ages ago still doesn't have a chance to ? Anyway, in 2010 there's only 1 Friday is in the 13th but in 2009 there are three months . People just never realize about it ..
Here is some superstitions that show the fear of this day .