One of the beliefs is that the origin of this superstition is linked to the Bible: there were 13 people at the last supper of Jesus and he was crucified on a Friday.
The tradition of Friday 13th doesn’t appear to be as old as you may think. It seems to have started in the UK at the beginning of the 1900s and then spread to other European countries.
Historically, there are 35 bad luck days during the year, based on a calculation by astronomer Tycho Brahe, who has mapped out which days to be careful.
So has anything spooky been happening in Sweden on this day? According to the Swedish Rescue Services Agency, which has looked into the statistics, more fire alarms are set off on this day than any other. But luckily, there are no more fires or accidents than usual.