In the Northern Hemisphere, summer solstice begins on June 21, 2011 at 1:16 P.M. EDT
Sol + stice derives from a combination of Latin words meaning "sun" + "to stand still." As the days lengthen, the sun rises higher and higher until it seems to stand still in the sky. As a major celestial event, the Summer Solstice results in the longest day and the shortest night of the year. The Northern Hemisphere celebrates in June, but the people on the Southern half of the earth have their longest summer day in December.Awed by the great power of the sun, civilizations have for centuries celebrated the first day of summer otherwise known as the Summer Solstice, Midsummer (see Shakespeare), St. John's Day, or the Wiccan Litha. The Celts & Slavs celebrated the first day of summer with dancing & bonfires to help increase the sun's energy. The Chinese marked the day by honoring Li, the Chinese Goddess of Light. Perhaps the most enduring modern ties with Summer Solstice were the Druids' celebration of the day as the "wedding of Heaven and Earth", resulting in the present day belief of a "lucky" wedding in June.

http://www.chiff.com/a/summer-solstice.htm