I've interviewed hundreds of people over the last decade about how schools in the United States often choose to structure time. Most often, I pose the question to people in the places I visit, "Can you explain how the school day is structured, and why?"
I've found that many people working within schools are usually split into two camps of thought:
1) The schedule is fine just the way it is.
2) We definitely could do things differently . . . but never quite get around to it.
With the majority of students and parents I interview, however, I find they fall into the second category, that the traditional concept of what the "school day" is could use an overhaul.