Question of the Day - 13 November 2020

[Editor's Note: This question was posed by the same QoDer who submitted one about the Ides of March that we answered last year. It seems he/she has landed on an effective method for getting a submission answered.] 

People who harbor a superstition about Friday the 13th might suffer from triskaidekaphobia, or a fear of the number 13. More specifically, paraskavedekatriaphobia and friggatriskaidekaphobia refer to a fear of Friday the 13th itself. 

In a fair amount of research on the subject, we were unable to come up with a definitive answer on where the idea that a Friday that falls on the 13th of the month is unlucky. We don't think it's known.

But we can say that Friday the 13th has a very long mythology of being considered unlucky. 

As far as we can tell, the earliest "evidence" that 13 might be an unlucky number is considered to appear in the Code of Hammurabi, a set of 282 rules for commercial transactions and social interactions that date back to around 1750 BCE in ancient Babylonia. For some reason, the Code skipped over the number 13, to which some observers ascribe superstitious significance. One writer on the subject went so far as to claim that the omission of 13 happened on a Friday, but we suspect that's apocryphal, considering that the seven-day week and the names of the days didn't show up for another 2,000 or so years -- during the reign of the Roman Emperor Constantine around 320 CE.

Also contemporary to the Romans, the Bible recounts that there were 13 attendees at the Last Supper: Jesus and the 12 apostles. This number has long inspired a superstition that hosting 13 at a table is a bad omen. In addition, the Last Supper was held on Maundy Thursday; the next day, Good Friday, Jesus was crucified. That's why Friday has traditionally been regarded as a day of abstinence and penance by Christians.

Similarly, in a Norse myth, the trickster god Loki was the 13th guest at a banquet and apparently killed several of the others.  

We also found some evidence from Biblical literalists that the entire episode in the Garden of Eden took place on the sixth day of creation (Friday). Thus, some believe that Eve ate the forbidden apple on a Friday. Similarly, as Kevin Lewis pointed out the last time this question ran, according to Christian tradition, Jesus was executed on a Friday.

Kevin also wrote, "The ancient Babylonians considered 12 to be a 'perfect' number because it is divisible by 1,2,3, and 4 (and likewise, 60, because it is divisible by 1,2,3,4, and 5). Thus, adding 1 to the number 12 made it 'imperfect.' As a practical matter, if you have 12 of something, you can divide it equally among 2-4 people; add one more, and you have an argument."

One of the most prevalent and popular myths attempting to explain the origin of the Friday the 13th superstition stems from what happened on Friday the 13th in October 1307, when hundreds of Knights Templar, a Catholic military order, were arrested across France, charged with heresy, sacrilege, and Satanism, and ultimately burned at the stake.

Then in the late 1300s, in his Canterbury Tales, Geoffrey Chaucer wrote that it was bad luck to start a journey or a project on a Friday.

Another superstition about the number 13 comes from around the 16th century, when witches were all the rage in Europe. It was believed that a "coven," or a gathering of witches, consisted of 13 women. 

A few centuries later during the highly superstitious Victorian era in the mid-1800s, someone somewhere put the two together, Friday and 13, and came up with the idea of a doubly unlucky day. 

And that localizes paraskevidekatriaphobia as a primarily northern European and (by extension to the colonies) American and Canadian superstition.