This is very impractical. The longer school day is possibly doable, but the rest is a joke. You can’t only close schools when business close because schools are liable if accidents happen. If we could sue our employer for making us go to work in dangerous weather, then maybe that would be ok, but as it is, the schools take a lot more responsibility for the well-being of their students than most businesses do for their employees.
Lunch schedules are arranged the way they are because they don’t have enough money for a large enough space for all the kids to eat at the same time.
Teachers can’t possibly extend the hours they work/teach by that much. Instead, you could have more people who are employed to provide after school activities that have bus transportation. It would be part time work, but high school/college students could work at elementary schools and provide tutoring/mentoring. Having clubs, athletics — not just for jocks, band, tutoring, counseling, play-time for younger kids, etc… would be very valuable, but also very pricey. It would be difficult to find enough people to cover the jobs that are actually qualified to work with kids in some areas (mostly poor or rural areas).
The saddest part to me, is that the extended school day could possibly happen in wealthy schools, but not in the poorer schools where they need it the most.