When is the first day of Summer in 2008?
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