I think in a perfect world, all screen time including tv, video games and internet use should be under two hours per day. So if my kids are watching a 90 min movie at night, they get 30 more min to use as they please.

My kids occassionally have 30 min of tv or ipad on weeknights, but thats it and only when time allows. On weekends, I try to stay under 2 hrs, but if weather is bad I have definitely broken that rule.