To be honest I think it would be better for children to have longer school days and much longer holidays, so shorter terms. Condense it basically, so that the vast majority of their life isn't focused on school. Whole days of freedom are more valuable than an extra free hour or two after school each day, where school will already have taken up the vast majority of their mental and physical energy. And in winter those after school hours are in the dark so useless for any outdoor activity. Longer school days would also be better for most working parents, and it would probably be cheaper to swap after school childcare for whole day activities in the school holidays.
I also think that the current "parental leave" policy should be scrapped because most people simply cannot afford to take this unpaid leave. It should be replaced by a more generous 2 weeks per year of extra paid leave at the rate of the person's actual salary/ earnings (so that everyone can afford to use it) for the years of primary school, funded by the Government. This would allow much more parental time with children (also important therefore to double the allowance to 4 weeks for single parents) and have huge benefits in terms of child mental health, adult mental health, raising secure and well-balanced children and children feeling rested and restored ready to go back to school and study, less stressed and more focused. And developmentally we know beyond doubt that children benefit enormously from significant time that is undirected. It's so unhealthy to put them on a treadmill of daily demands at such a young age and crushes their imaginations and creativity.
We need to focus our Government policy more on wellbeing and quality of life given that's the entire point of having an economy in the first place. Currently, because they do not have a vote, funding for anything related to children is even more woeful than everything else: education (right from early years through to university), children's services, CAMHS, means testing even of child benefit/ childcare funding which is an abomination. We need to unashamedly say "yes, children are the most vulnerable members of our society and the future of it, and it benefits us all to fund this, even those who do not have children."
Looking back to childhood many people's fondest memories will be of their summer holidays. It should be a priority and the idea it should be curtailed rather than looking at policies to extend it/ increase the quality of it as family time are bizarre to me and very short-sighted.