According to the Stress Management Center and Phobia Institute in Asheville, North Carolina, an estimated 17 to 21 million people in the United States are affected by a fear of Friday the 13th. This makes it the most feared day and date in history.
But why?
Friday the 13th: A Biblical Superstition?
According to Dr. Phillips Stevens Jr., Associate Professor of Anthropology at Buffalo University's College of Arts and Sciences, there is a strong taboo about 13 and Friday.
"Most buildings don't have a 13th floor, you won't find 13 people seated a table and some airlines don't have a 13th row," Stevens said. "The taboo comes directly from Biblical stories."
The Biblical story that Stevens is referring to is the Last Supper, where most of the Friday the 13th superstitions are rooted.
In the Bible, Jesus and his twelve disciples gathered for the Last Supper on Thursday. Judas is considered the 13th disciple, if you include Jesus. Judas betrayed Jesus and sold him to the Romans, leading to His crucifixion the next day, which was a Friday.
Stevens said that superstitions involve mankind's belief that things in our universe are interconnected and have causal relationships. Therefore people connect certain things with good luck or protection, like the Christian cross. Adversely, many people, including non-Christians, associate Friday and 13 with something that should be avoided due to those events in Biblical history.
"The crucifixion was a great tragedy, it was the murder of Christ and it happened on a Friday," Stevens said. "There were also 13 people at the Last Supper and the 13th was the one who betrayed Jesus. It is considered a very powerful, Earth-changing day."
Friday the 13th: Other Explanations
Joe Nickell, an investigative writer for the Skeptical Inquirer Magazine, also believes 13 is historically regarded as disastrous.
"Various religions and mythologies have the number 12 as a representation of completeness," Nickell said. "There are 12 Zodiac signs, 12 months and there were 12 disciples."
He indicates that there is an idea that one more than 12 is a step away from completeness or a step towards evil and disaster. He also points to the Bible as being a source of the superstitions around Friday the 13th.
Some historians believe that the Christian distrust of Friday is linked to the early Catholic Church's suppression of pagan religions.
According to the Roman calendar, Friday was devoted to the goddess of love, Venus. When Norsemen adopted the calendar, they named the day Freya after the Norse goddess of sexuality.
The theory says that the Christian church vilified the day of Friday for this.