DS has always had bath at 7pm, into bed by 7.30 (although I may be still reading a story at this point).

Even when it took him hours to go to sleep (he WAS tired, he was just in a lot of pain, before people go on about "if they're not asleep in 20 minutes they aren't tired", which I HATE, try living my life and say that) we did bath at 7pm unless he asked for it earlier. And he does sometimes.