Can I schedule Do Not Disturb for specific days?
Sadly, on a non jailbroken phone you can only set Do Not Disturb to set hours, regardless of which day.  Therefore, every day gets the same hours.

What would be nice, would be a system like the alarms where you can set multiple ones and have them repeat on choosable days, then you could set 2 DND period, one to cover weekdays, and one for weekends etc.

I would recommend making a feature request at this link.