My auto insurance company, which has incredible amounts of data at its disposal, covering practically every aspect of modern life, wanted to know what degrees I had and in what fields. If I'd been an engineer or a teacher, they'd have given me better rates. They have discounts for things I would never have thought of. They have no discount for drivers who stay home on Friday the 13th. And I've heard of studies which found that this particular date is no unluckier than any other.
Anyway, what is "logically possible" about "unlucky Friday the 13th?" Especially since the calendar is utterly arbitrary (slide a day from July to June and you change everything)--actually, just mentioning the calendar around here can--well, I guess you've seen it. What logical theory suggests that that particular day is different?