Eve of May Day WordNet 3.0 & Open English WordNet

Walpurgis Night, an abbreviation of Saint Walpurgis Night, also known as Saint Walpurga's Eve, is the eve of the Christian feast day of Saint Walpurga, an 8th-century abbess in Francia, and is celebrated on the night of 30 April and the day of 1 May. Wikipedia

A holiday celebrated in Central and Northern Europe Wikipedia Disambiguation

Germanic festival celebrating the start of summer Wikidata

A celebration in the night from April 30 to May 1 which traces back to pagan traditions. OmegaWiki