alt Hacker NewsAll the schools in my area have before and after school programs for parents that both work or single parents or any other reason you want your kids to be at school longer. I recall my school as a kid had it as well. There isn't traditional class work but it serves as additional recess before and after school as well as lets age groups mix. There is a lot of social learning that happens in that setting that is good for the kids.
I agree with all of that. The problem in our area - I realize every local (US) school system is different, which itself seems to me to be a problem - is that the after school program is enormously expensive. Our kid is skipping (public) TK to stay another year in his private (all day) pre-school because TK + after-school is only, like, $50 / month cheaper. Not sure why three hours of after-school costs the same as 7.5 hours of Montessori, but it does.