Midsummer celebration with roots in pagan rites is known as NOC KUPALNA or NOC KUPAŁY (Kupala Night) or SOBÓTKA and continued in Christian tradition as NOC ŚWIĘTOJAŃSKA (Saint John Eve).

The timing is related to the summer solstice
(falling this year on June 20 at 11:24pm CDT) and
nativity of St. John the Baptist (June 23-24).

Kupala rites involve dancing around and jumping over the bonfires, searching for magical flowers in the woods and floating flower wraths on rivers and lakes.