Walpurgis Night

eve of May Day (in medieval German folklore this was the evening when witches came together and met); wild festivities or an event or situation that have a nightmarish quality

Walpurgis Night is a holiday celebrated on April 30 or May 1, in large parts of Central and Northern Europe.
See more at Wikipedia.org...

Noun
1. eve of May Day
(hypernym) day

[Folklore] The day of the Saint Walburga (8th century CE) is celebrated on May 1. But the night before, April 30 or May Day Eve (Beltane Eve), is called Walpurgis Night; formerly the date of the pagan festival marking the beginning of summer. According to German legend, this festival has been associated with a witches' carnival, and on this night it was believed that witches met with the devil. In these nights there were usually large bonfires in certain places in the Harz Mountains, Germany, with the purpose to dispel witches.

Eng: walpurgis night
Urdu: وال پرگس رات ۔ وسطی دور کے جرمن اساطیری قصوں کے مُطابِق وہ شام جب بہت سی جادوگِرنیاں ایک طے شُدہ مقام ۔