Wow. I can't imagine having kids in school until 6:00PM in order to mirror the workday of parents. This is what a school district in Colorado is doing as a participant in a pilot program and in exchange for $1 million. Districts in five other states will be participating as well.
Here's the story on the Denver-area schools: http://www.denverpost.com/ci_22115984/colorado-gets-1-million-study-lengthening-school-days 
And here's a story from the New York Times that's a bit more general: http://www.nytimes.com/2012/12/03/education/school-districts-in-5-states-will-lengthen-their-calendars.html 
I would not be a fan of this idea if it was brought to our state, but I could see how it might appeal to some. I just worry about how the kids are going to have time to unwind or even participate in any extracurricular activities if they're being released at 6:00PM.