St. John's Day is celebrated on June 24, 2017 and the official feast is called the Nativity of St. John the Baptist. St. John's Day is the anniversary of the birthday of St. John, the Baptist on June 24 and is connected to the Midsummer Day on June 21. Nearly all Christian churches celebrate St. John's Day. It is also known as Nativity of the Forerunner. In the shortest night of the year from June 23 to June 24 Saint John's Eve is celebrated annually.
There are a lot of costumes associated with St. John's Day. One of them is the enlightening of the St. John's bonfire at the night before the holy church day St. John's and the dancing around it. The Saint John's bonfire is a midsummer symbol and is often simply called The Fire. Most European countries have their own traditions and customs for St. John's Eve, like the Bonfire Night in Ireland and huge family dinners in Denmark.
In the Northern hemisphere St. John's Day is considered as a day for weather foreshadowing. Around St. John's the perennial herb St. John's Wort and Yarrow blooms. It is a tradition to pluck some of them on St. John's Eve. Also ribes are ready for harvest and therefore in Germany for example named after the Saint. Fireflies are also associated with the feast of Saint John as they glow brightest around that midsummer time.
The date for St. John's has been moved to the 24th of June because it is said that St. John the Baptist is six months older than Jesus Christ. He was a preacher of repentance and is considered the last relevant one of Jesus' disciples by the Christian Church. St. John is among Mary and Jesus the only person whose birthday is a feast day - usually a saint's commemoration day is his or her death day.