Why do people fear Friday the 13th as an unlucky day?

There is always at least one "Friday the 13th" in a year.

This year there were two such days, yet not as many people, groups or organisations play upon "Friday the 13th" like they do with Halloween.

But that is a-changing. And just mention that South Africa's "Mystery Ghost Tours" will hold their second discount ticket priced ghost tour tomorrow, then like the last "Friday the 13th" ghost tour this year, the tour is likely to become fully booked.

This even though most people don't know the origins of the superstition regarding the number 13, nor why the number landing a date on a Friday is worse.

But so it is with "Friggatriskaidekaphobia" - the proper term for the fear of "Friday the 13th" - the word "frigga" being the Old Norse word for Friday, and "treiskaideka" meaning 13 in Ancient Greek.

For the longest time there has been no number 13 for seats on airplanes, cabins on ships, rooms in hotels, and so on.