We had set bedtimes that changed as we got older (but that also were more lenient the younger you were in the pecking order). I know that when I was in 5th grade I had to have special dispensation to stay up and watch the Beatles on Ed Sullivan – my bedtime was 8 pm and they came on at 8:30. By the time I was in high school it was lights out at 10 pm.
My kids have set bedtimes. My son (age 14) has a time of 9 pm, because he argues and fools around so much before actually falling asleep. My daughter goes to bed at 10 pm because she is into sports and has to be at school early everyday.
The only time this is altered is for special events (a big tournament or a church activity or a school dance or a sleep over) or when the kids go visit their cousins, who have no set bedtime. Their parents are both night people and tend to really come awake about 9 pm.
As far as dinner goes, when I was growing up dinner was at a set time (at first at 5 pm when we were small, but gradually later, especially after we lived in South America for a while) and you HAD to be home for dinner. With my kids we are a bit more flexible in that they have busy schedules (especially my daughter). However, they know that if they miss dinner they have to scavenge for themselves in the kitchen. I don’t cook twice in one night.