Friggatriskaidekaphobia – an irrational fear of Friday 13th. Frigga is a Norse goddess of fertility and love for whom Friday was named. In the Middle Ages all Fridays were bad luck, definitely not a day to marry or embark on travels. Christianity feed superstition – 13 seated at the Last Supper, Judas said to be the 13th guest and claims Jesus was crucified on a Friday. As far as Christians were concerned Friday was the “witches’ Sabbath” (clearly Pagan namesake Frigga had to be a witch ).
May 13 is the only Friday 13th of 2016. For phobics of 13 – it falls exactly 26 weeks ( 2 x 13 ) since the last one in November 2015, precisely 65 weeks ( 5 x 13 ) after February 13, 2015, the first of 3 last year. 2017 will have two, January and October, 39 weeks ( 3 x 13 ) apart.
When leap years start on a Friday there’s only one that year, always Friday 13th of May. Dates and days realign every 28 years, therefore leap years 28 years apart start on Friday, making May 1 a Sunday ( months starting on Sunday always have Friday 13th ). The only exception being leap years not divisible by 400 ( next one 2100 ), 2100 begins on a Friday but since Gregorian rules won’t let it leap, the 365 day “common year” hasn’t a month starting on Sunday until August.
Whether Friday 13th is inconsequential, perpetrator of mild superstition or responsible for phobia induced panic attacks, let me point out – there aren’t any witches. Friday 13th is a precise mathematical calculation based on the Gregorian Calendar. Nothing Frigggatriskaidekaphobia to fret about.