Why in the world are there designated time periods for family allowances in the first place? Why can't I pick my own time periods? If you have the basic the capability for us to restrict our children's use of their phones, how could it be any more difficult to allow us to set our own schedules? Let's say that for some reason you did have to predefine schedules, how did you decide to lump Friday night in with the weekdays and Sunday as a weekend? If anything it should be one setting for Sunday - Thursday night and another for Friday and Saturday.
This is a great idea and is so close to being a useful feature, but some simple, bone-headed design choices have spoiled it entirely and made the whole experience enormously frustrating. This really ought to be easy to correct. Why not do it? I know many others have complained about this already.