Midsummer's night

In Norway, as in Denmark, Sankthansaften [Midsummer] is celebrated on June 23. The day is also called Jonsok, which means "John's wake", important in Roman Catholic times with pilgrimages to churches and holy springs. For instance, up until 1840 there was a pilgrimage to the stave church in Røldal (southwest Norway) whose crucifix was said to have healing powers. Today, however, Sankthansaften is largely regarded as a secular or even pre-Christian event.
In most places the main event is the burning of a large bonfire. In parts of Norway a custom of arranging mock marriages, both between adults and between children, is still kept alive. The wedding was meant to symbolize the blossoming of new life. Such weddings are known to have taken place in the 1800s, but the custom is believed to be older.
It is also said that if a girl puts flowers under her pillow that night, she will dream of her future husband.

Hey, the longest day of the year? Middle of summer? I know! Let's build a huge bonfire and pretend to get married. This probably seemed like a good idea after the herring and the aquavit.