You're right, of course, if the current 39-week/32 hour Monday-Friday model continues unchanged, and you carry on teaching in the way that you are required to do at the moment.
This model of education is Victorian and reflects the needs of the new industrial workers of that era. The overall school/academic year reflects an earlier medieval religious/agricultural calendar.
So, the structure of the school calendar has never really been about the needs of children. Now, it's completely outmoded and doesn't reflect the way many adults and families function in the 21st Century.
Now imagine an education system free from these constraints. A system based on the needs of the child, not the institution. A system with bookable holidays (imagine!) and flexible end-point assessments.
With creative thinking we could have a compulsory education system that fits around families, not schools, but delivers results and, most importantly, reminds parents of their duty to bring up their child.
Of course the unions will fight any change, but their self-interest means that they don't - and haven't as far back as I can remember - have the interests of teachers, children or parents in mind anyway.
OK, have a giggle at all of this ... but just imagine how it could be.