Ooooh. With all the red tape the government puts on schools these days, the number of days almost requires the early start. Districts are forced to compete for test scores which means they have to get as many days of instruction in as possible before the dreaded state test in April (Sure they could change the testing dates, but that would require action by government officials.). Besides, the patrons of our schools will not - in fact, they will refuse to - send their kids to school in June (regardless of legal attendance requirements).
As for the breaks, try spending five days a week with 25 preteens or pubescent middle schoolers and try to teach them the parts of speech or how to figure the area of a growing circle. You'll need a break - especially between Christmas and Spring Break. As for our school, we really don't let out for much beyond holidays, and our patrons have indicated that we are one of the districts in the nation that has the What Parents Want reward.
That being said, the biggest waste in education, these days, is made because of the strings being attached by politicians in state capitals and in the federal government. We could reduce our staff, save money by consolidating and pinpoint staff development, and simplify so many processes, if the politicians would stop pretending they have more expertise than the educated staffs and administrators in local school districts.
Oh look, I have strayed so far off topic I'm going to need GPS to get me back on the grid.