Ontario, Canada has all but eliminated homework entirely until high school. There is absolutely no good data saying it helps in acquisition or retention of skills over the long term. Completion of homework is also strongly correlated along class lines. If Suzy has a stable home, is fed well, and gets good sleep, she will likely have time and resources to complete homework. If Todd doesn’t, he likely won’t. We should focus on the in-school instruction. As far as the length of day? If you keep the kids longer it will cost more so it’s unlikely many jurisdictions will raise taxes for that expenditure.