I have 4 dc's, aged 7, 5, 20m and 6m.
I always put the eldest 3 to bed at 7.30pm. No matter if it's a school night, weekend or school holidays. They do of course have the occasional late night if we have been out somewhere.
Family and friends, even neighbours children who stay up later than mine esp in the holidays, have said it is mean to not let them stay up later.
We have tried ds1 with a later bedtime but he gets so tired and stropy the next day he is a nightmare. Also true if 20m has late night. IMO they are getting the right amount of sleep they need. They don't wake up extremely early, almost always between 7-7.30am.
Surely I am not being mean?