Saint Hans v/s Midsummer
Vikings and Germanic people used to celebrate the Midsummer feast around the 23rd of June. The reason is that that day, is the longest day of the year and from that point of time, it can only stay less time in the sky. To give the sun more strength, the popular belief was to light fire as high as the sky. This was a day of celebration and where that was though the gods were closer to the people.
When Christians came, trying to convert most of the pagan traditions, they impose the fact that Saint John the Baptist was born 6 months before Jesus and that day the devil is around, so the fire is a way to purify and fight the evil (therefore witch burning day), exactly the 24th of June, switching the tradition and changing the purpose of it.
