An editorial in today’s Washington Post examines the debate over school start times. It shows just how complex it can be to make changes to daily school schedules.A proposal in Fairfax County, Va., would change the start time of most high schools in the county from 7:20 a.m. to 8:30 a.m. It appears that there is strong support for a change. But there are also many obstacles.Money is one concern.