My son is 12 years old and spends several hours a day on a PC. When I want to drive it away, he says that classmates can also be on a PC for several hours a day. Can't it hurt him? Do you leave children at home on a PC for a few hours?
He has to judge for himself. It is very difficult to determine any particular suitable time. Personally, I would lean according to the other interests and age of the child to 1-2 hours.