A day of superstition. But why?
It all started at dawn on Friday, October 13, 1307 when King Philip IV ordered scores of French Templars to be arrested simultaneously. It's believed that this was the beginning of Friday the 13th superstition.
The superstition of 13 dates back even further. Old Norse mythology states that Loki was the 13th guest to arrive at a Valhalla banquet - which ended in the death of the god Baldur. Babylonians also saw 13 as unlucky due to its indivisibility. Christianity also has a link to the date, as Good Friday marked the execution.
The fear of the number 13 is so prominent that it has a name: triskaidekaphobia. The fear of Friday the 13th specifically is paraskavedekatriaphobia.
But don't worry! There can never be more than three Friday the 13ths in one year (2018 had two). The longest period of time that can pass with no Friday the 13ths is fourteen months. The next to occur is September 13, 2019 - fourteen months from today.
Of course if you really do fear Friday the 13th, you can jet on over to Paris, where you can hire a quatorzieme (professional 14th guest) to remove the supposed bad luck.