Walpurgis Night (Walpurgisnacht) is a traditional spring festival on 30 April or 1 May in large parts of Central and Northern Europe. It is often celebrated with dancing and bonfires. It is exactly six months from All Hallows' Eve.
The eve of May Day, traditionally celebrated with dancing, came to be known as Walpurgisnacht ("Walpurga's night").
The 17th century German tradition of a meeting of sorcerers and witches on May Day is influenced by the descriptions of Witches' Sabbaths in 15th and 16th century literature