According to Wikipedia, a solstice is "an astronomical event that happens twice each year, when the tilt of the Earth's axis is most inclined toward or away from the Sun, causing the Sun's apparent position in the sky to reach its northernmost or southernmost extreme. The name is derived from the Latin sol (sun) and sistere (to stand still), because at the solstices, the Sun stands still in declination....that is, the apparent movement of the Sun's path north or south comes to a stop before reversing direction. As a major celestial event, the Summer Solstice results in the longest day and the shortest night of the year.
At the Tropic of Cancer (23°26'N) and all points to the north, and at the Tropic of Capricorn (23°26'S) and all points to the south, the sun reaches its highest position in the sky on the day of the Summer Solstice. Depending on the shift of the calendar, the Summer Solstice occurs sometime between December 21 and December 22 each year in the Southern Hemisphere, and between June 20 and June 21 in the Northern Hemisphere" ....and today is June 21st!