This is in the Netherlands. Based on a normal schoolday, with college/uni as an exception, since those times varies per study/classes/courses you follow.

Elementary school: 9:00-15:00

Secondary school: 8:30-16:00

College/uni: 0~10hours (with 0 i mean people tend to skip a lot of classes 😂)

Fungo, Olessia is correct.

When I was a student, in Junior School we used to have 5 lessons a day 6 days a week.
They were discussing making it 5 days, but they thought that it's hard for kids to have that many lessons. In high school in the year of graduation it was 6 lessons a day.

7:00 - 20:00 do you mean 13 hours of lessons a day? It is much more than what university students have here;/

When i was at high school I started at 8.15 and finished at 13

8 hours. Indonesia