Friday the 13th is considered unlucky in Western tradition. It happens when the 13th day of the month in the Gregorian calendar falls on a Friday, which happens at least once a year but may happen up to three times in a single year. Friday the 13th happens on the 13th of every month that begins on a Sunday. All other Fridays in the month are considered regular days.
Some examples: 2013 was a Friday the 13th month twice - first in January and then again in March. 2014 will be a Friday the 13th month once - in February.
The term "Friday the 13th" became popular after it was used by horror movie director Sean Cunningham to describe one of his films in 1987. The phrase has since been used by other filmmakers.
It's important to note that this date is not special in any way beyond its occurrence every year. Any date between April 30 and October 31 can replace it, with no effect on any object, activity, or occurrence.
However, some things do make Friday the 13th more dangerous than other days. Here are the details:
There is no evidence to support the idea that anything bad will happen on this day. However, there are several myths and legends surrounding this date.
Every year, Friday the 13th happens one to three times. This day is considered unlucky in many places throughout the world and is associated with misfortunes. There are 52 weeks in a year and if we divide 2013 by 4 we will get an average of 13 Fridays the 13th per year.
Fridays the 13th were first noted on calendars in 1582 when Martin Luther published his calendar. Before this time, dates didn't have specific days of the week attached to them so it was hard to know what date would come up next. Martin Luther noticed that Thursday had become Friday over time so he added one more Friday to the year to make up for it. He called this day "Fridericus" which means "Friday."
Today's date is Friday, January 13, 2015. It is the third Friday of 2013 and since Monday is a holiday, today is the last weekday of 2012.
There are two types of Fridays the 13th: common and rare. A common Friday the 13th occurs once every 12 years while a rare Friday the 13th happens twice in any 16-year period. Because 2013 is a common year, it will be a Friday the 13th once every 12 years starting with this year's event.
There is little evidence to suggest that Friday the 13th is an unlucky day. Numerous studies have found that Friday the 13th has little or no influence on occurrences such as car accidents, hospital visits, and natural catastrophes. 11.6% of the days of the year are Friday the 13th, so it makes sense that these would be "unlucky" days.
However, it's possible that this number may be higher due to lack of data. For example, if there were no plane flights on Friday the 13th, it might be considered an unlucky day for travelers. Also, since most fatal accidents occur within three months of the initial prediction, it's possible that more accidents will be reported on Friday the 13th than other days of the week because people are likely to blame the accident on bad luck rather than industry standards.
The best way to avoid being cursed by Friday the 13th is to not worry about it. If you're having problems with accidents, illness, or other negative events, there must be a reason for it. Looking for bad luck everywhere will only make matters worse.