Why did schools start and finish early in Roman Life?

In the early days, when Rome was a kingdom, kids did not go to school. Education took place in the home and was done by the family. If a family had someone who knew how to read and write, the boys were taught how. They were also taught how to be warriors. Finally, they were taught how to manage the farm or business and how to behave in society. All this teaching was done by other males in the household.