When I was a kid we had a Sunday roast most weeks especially in the winter, and it was always served around 3pm ish, maybe an hour earlier or later.
That for me is 'normal' time to have a roast. In fact a lot of pubs and carveries round us only open until 3 or 4 for lunch and then close Sunday evening.
DH's family though consider 'Sunday Dinner' to be dinner and serve between 6 & 7 which for me seems really late!
So, out of nothing more than curiosity, what time would you serve a Sunday roast? (Also what part of the country are you in, in case it's a regional variation?).