Obama is lucky kids don't vote. And I could see making summer break shorter having some positives, but longer school days would be counterproductive, especially as students now have more homework than in past generations.
Who wants to try a bottle of merc's "Extroversion Olive Oil?"
Numbers indicate that the greatest socioeconomic imbalance in school performance is due to the lengthy summer vacation, other than parental involvement. This isn't just coming out of nowhere - wealthier kids do educational things like go on trips and visit museums during the summer. Poorer kids are stuck in front of the TV or Xbox to keep them out of trouble while the parents are at work.
In all honesty, it's the one biggest thing that can be done policywise to increase educational performance. Of course, that doesn't mean we'd be going to school longer; we'd just space holidays out over the year. Two weeks every six weeks, with a month-long holiday at Christmas and in the middle of summer.
I don't think it necessarily needs to be as intense as countries like China, Japan or Taiwan but 3 months really is too long. 6-8 weeks would work better. Think what you're losing out on if you miss a month's worth of education every year of your school life.
I never fully understood the US system. Do you have terms/semesters/whatever with breaks in between? Or are the only days that you have off during the school year statutory holidays? What's the format as it stands? And how long is the average American school day now?