until 2 weeks before, even though I find this irritating as a fan trying to make plans (I, too, have young kids).
I think it is all determined by TV schedulers. There are sweet spots in the rankings/matchups that give you better times. If our game is the most interesting game in the country or the least interesting, I think we get a nice, mid-day kickoff. Otherwise, we get pushed all over and you can't find out anything.