Every one of us is familiar with the relaxation of summer vacation. However this relaxing three month period of unwinding, fun, and excitement was once a time for kids to work.
The school year used to be based on an agarian schedule of harvests and growing seasons. However kids were most needed in the spring to harvest and in the fall to plant. So in actuality the school calender would look more like a short period of school in the summer and a short period of school in the winter.
In urban areas the schedule was more similar to our modern schedule. It was year round, with small frequent breaks throughout the year. However it was not always mandatory to attend, and kids would often take off the summer months to vacation to cooler climates with their families.
In the nineteenth century people began to push for a standarized summer schedule among rural and urban areas. They decided on summer as a time for break, without taking productivity of academic acheivement as a factor in this decision. There was a theory that people would get sick if they were so stressed in school for too long, so summer vacation was intended to create leisure time for children and adults to relax and unwind.