First day of summer 2008

June 20th was the first day of summer for 2008. The first day of summer is also the summer solstice.

Solstices occur twice a year, when the tilt of the Earth's axis is most oriented toward or away from the Sun, causing the Sun to reach its northernmost and southernmost extremes. 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, its apparent movement north or south comes to a standstill.

The term solstice can also be used in a wider sense, as the date (day) that such a passage happens. The solstices, together with the equinoxes, are connected with the seasons. In some languages they are considered to start or separate the seasons; in others they are considered to be centre points (in English, in the Northern hemisphere, for example, the period around the June solstice is known as midsummer, and Midsummer's Day is 24 June, about three days after the solstice itself). Similarly 25 December is the start of the Christmas celebration, which was a Pagan festival in pre-Christian times, and is the day the sun begins to return back to the northern hemisphere.

It depends where you live, since the first day of summer is timed with the summer solstice. For most of the United States, summer begins on June 20. In Europe it's June 21. In Australia it's six months later, on December 21.

See dates for 2008 at http://www.archaeoastronomy.com/2008.shtml

Also see http://aa.usno.navy.mil/data/docs/EarthSeasons.php

On the other hand, if you are looking for an "official" first day of summer, there is no such thing. The United States, for instance, has never declared when the seasons start. The International Astronomical Union hasn't either. In many areas of Europe, May 1st is considered the first day of summer (as the meterologists in the United States do) with the Summer Solstice being the "Midsummer" (as in Shakespeare's play).