Between 7 -8pm for ours who is nearly 6yrs.
On the weekends (Fri or Sat nites) it will be the same unless there is something different happening or good movie on or we have promised as treat to stay up later.

Recently we have made some bedtime changes cause DS wasnt going to sleep till at least 9.30 even if was in bed by 7pm.
We tell him he has 10 mins light on time for reading after we have said g`nite and then we turn it off. We are shutting his door a bit more than the open we use to do and tell him that if he talks we will have to shut the door properly. So far (past 3 weeks) this has worked well and he is mostly asleep by 8.30pm. He either doesnt want his door shut, so goes off to sleep, or if we we shut it he goes to sleep quick too. He also has a little night light, but if he is really talking etc then we tell him we will take that off him - which we havent had to do yet. We also stopped playing a night time cd at bedtime, as much as it used to help him get to sleep when he was younger, we have found it was now preventing him.
Oh, and we have also told him that if he needs to pee or water, then to get up quickly and quietly and go do that, then get back in bed. We leave a cup in the bathroom for him, so he doesnt have to come and get us to help in the kitchen.