Growing up, I moved around enough that summer holidays changed according to where I was and the needs of the area. One place I lived summer holidays actually happened in November when the coffee crop was ready to pick because too many of the students earned money for the year that way.
When I lived in Australia, the school year was spread out with two weeks between terms and six weeks off in the summer. I heard that places are offering year round school where you choose which quarters you attend and when you want off.
The summer holidays we have in Alaska run mid may to around the beginning of August because of the traditional fishing season. Much of rural Alaska still relies on subsistence hunting for winter food and subsistence follows various seasons. There is a lot of fish that can be gathered during the summer. In addition, many students spend their summers earning money on fishing boats.
Through all this, I've wondered if the story that summer holidays happen because students were needed to work the farms is true. After reading several articles which indicate this country's agrarian history had quite an impact on more than the length of the school year, I've found sources which dispute this claim.
The claim is simply that students needed to be home from school early in the day so they could help around the farm with various chores, thus the tradition of letting students out by 3:30. They needed the summer off to help with most of the growing and harvesting of crops but I found a could sources disputing this.
According to something provided by PBS, there was more to it than that. At one point the schools of New York city were open 248 days a year but along the way, the school year decreased because buildings in the city could get extremely hot due to the lack of modern air conditioning. Having summer holidays allowed those who could afford to escape to the country do so and enjoy a much cooler time. By the late 19th century, urban and rural areas began using a standardized calendar which allowed all students have the same amount of time off.
So now, we see a move to make the school year longer in both hours and year length. Will it succeed? I don't know. Let me know what you think, I'd love to hear.