In Soviet Union times in eighties in Belarus it was considered ok that a child could stay alone at home from age of 7 when they started a school. Some parents opted for after-school programs and some relied on grandmothers like it was for me but some of my schoolmates stayed at home alone for few hours until their mothers would be back from work (fathers typically worked longer and further away from home).

And from the age of 9 there was no after-school options at least in my school.