August 19th, as does my stepson at a charter school. I teach at an independent school and start the day after Labor Day.
My school has fewer days than the public schools in the state, but each day is a little longer to make up for it. Honestly, I think Singapore's school calendar would be ideal. It's 200 days, and I really think it would benefit the students. (Plus I'd get paid more... hopefully). Their breaks are spread out over the year with a month off in the summer, a month off in the winter, and a week off in spring and fall.