Millions of consumers alter their usual buying behaviour this Friday, merely because it is the 13th.
For those who don't buy into superstition, this presents some unusual opportunities to pick up a bargain.
There are two Friday 13ths this year, which tends to be standard.
In 2015 there were three - a particularly unlucky year.
Statistically there seems to be less likelihood of accidents or other unfortunate events on Friday 13ths, according to insurance data, because drivers and homeowners are extra cautious.
Adam Powell, head of operations at broker Policy Expert, said: “These figures suggest the UK remains superstitious as ever and that historically we take extra care around that unlucky date."
But for those who aren't hiding under the covers all day, there are some strange savings to be made.
Book a bargain flight (although check when the 13th falls)
Flyers not prone to superstition should check prices on Friday 13th.
Last year, on Friday 13 May 2016, prices for flights to the UK’s ten most popular destinations were on average 14pc cheaper than those departing on any other day in the month.
Kayak, a flight booking website, found that travellers could save a huge 44pc on a flight to Gran Canaria who flew on Friday 13 January.