We have a limit at an hour a day. But, that's after the homework and chores are done, otherwise it's a fight to get them started on that stuff. On the weekends we are a little more flexible.
I think it depends on age. So far my daughter isn't very interested in the TV, though I expect that may change as she gets older. I am trying not to use TV as a treat or reward, as I worry that will make it more important than it is.
