friday the 13th

Friday the 13th is considered an unlucky day in Western superstition. It occurs when the 13th day of the month in the Gregorian calendar falls on a Friday, which happens at least once every year but can occur up to three times in the same year.[1] In 2017, it occurred twice, on January 13 and October 13. There will be two Friday the 13ths per year until 2020, where 2021 and 2022 will have just one occurrence.

SOCIAL IMPECT

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 this day, making it the most feared day and date in history. Some people are so paralyzed by fear that they avoid their normal routines in doing business, taking flights or even getting out of bed. "It's been estimated that [US]$800 or $900 million is lost in business on this day". Despite this, representatives for both Delta Air Lines and Continental Airlines (the latter now merged into United Airlines) have stated that their airlines do not suffer from any noticeable drop in travel on those Fridays.

RATE OF ACCIDENT
A study in the British Medical Journal, published in 1993, concluded that there "is a significant level of traffic-related incidences on Friday the 13th as opposed to a random day