I'm totally against lengthening the school year or even the school day. My reason is these kids need a break from school and need to get outside and play. We are all for giving adults breaks, but what about kids? They're human, too, and need rest just like their parents do. I think having only 6-8 weeks off between the spring and fall semesters is not enough. Kids need 10-12 weeks off. I like the school day and school year the way they are. Plus, some of children's best education comes from play and home.
Kids around the world manage and I am sure American kids will manage too. If not, they deserve to be crushed by those hardworking kids around the world. I am against extending the school day though.