School hols childcare tends to be mainly the 8.30-3.30 variety i.e school hours. £60-80 a week often run by dance schools, football, gymnastics etc. But open to all kids not just those who go for weekly lessons. Cut off is usually 11 though so for primary aged kids.
Longer hours are rare around here, I know one nursery runs a holiday club 7.30-6pm but you are looking at £25 a day. DD's school runs childcare for a few weeks in summer 8.30-5 same price. Or a cm.
Mine is age 10 and i've been keeping an eye out of schemes that go older. The assumption is secondary school age don't need childcare.
Summers for DD are 1 or 2 weeks with me, 1 or 2 weeks on holiday at grandmas, week activity holiday, week at local dance school takes til 11, week at ballet school takes until 16 but only for invited pupils, her school runs childcare in summer so she sometimes goes there.
I only work partime so will do childcare swaps too - i'll have your fri if you have mine monday type of thing with another mum at school.
Some employers offer childcare vouchers (salary sacrifice) you can save then all year and use for some childcare eg pgl activity holidays take vouchers. Not all accept them though.