DD goes down anywhere between 6.30 and 7pm for us, she is normally well and truly exhausted by then. She naps twice a day so it does depend on when she's up from her afternoon one. We wanted to eat together too but she couldn't stay up that late (we used to eat round 7/7.30pm) so we moved our dinner earlier til around 5.30/6pm. Was really hard to get used to but now it's easier, and it's worth it to eat as a family.

I'm with the PP, if it's working for you guys then stick with what works