Not trying to defend Dish, but based on different movies having different "terms", I suspect the conditions are forced on Dish (and us) by the "owner" of the films. There's likely no set rule.... You do have to pay attention to what it tells you in that prompt and plan accordingly.
When we DVR a PPV like that, it throws an add'l kink into the original thinking of PPV. Remember, normal PPVs start at fixed times, be it 2pm, 4:30pm, etc. I think the idea originally was you select a later showing and get your soda, popcorn, and family gathered around the TV to watch it when it starts. That 5:30 warning, if I recall, is a holdover (pre-DVR days) from when you could rent the 2:00pm event but also watch the 4:30pm, 7:00pm, and later showings, up until 5:30am.
