Next Friday is the 13th !!!
Why is Friday the 13th considered such an unlucky day?
The reasons why Friday came to be regarded as a day of bad luck have been obscured by the mists of time — some of the more common theories link it to some significant events in Christian tradition said to have taken place on Friday, such as the Crucifixion, Eve's offering the apple to Adam in the Garden of Eden, the beginning of the Great Flood, or the confusion at the Tower of Babel.
The number 13 also has some religious symbolism as there were 13 people at The Last Supper of Jesus, who was incidentally crucified on Good Friday, but no evidence has been found that Friday 13th was considered especially unlucky until the 19th century. The number 13, however, has a long history of association with ill-luck. It has been linked to the fact that a lunisolar calendar must have 13 months in some years, while the solar Gregorian calendar and lunar Islamic calendar always have 12 months in a year.
There is also another theory that Friday the 13th of October 1307 was the day that Philip IV of France arrested and subsequenty tortured and killed hundreds of the French Knights Templar to get their money for the French treasury. One other note which predates all of the aforementioned is that the first Passover seems to have occurred on Friday the 13th. The death of the firstborns of Egypt occurred on a Shabbat on the 14th of Nisan in the evening. But the Jewish calendar counts days from sunset to sunset so this would have been Friday the 13th in terms of the gentile reckoning of the days.
Feminists have argued that because of the lunar year and Friday being named after a goddess in most European pagan calendars, the fear of Friday the 13th is a patriarchal invention, associating femininity with bad luck.
By the way, the fear of Friday the 13th is called paraskevidekatriaphobia.