Do children have regular "earlier than adult" bed-times anymore?

For about 20 years now, I have noticed children with parents in 24-hour grocery stores and other retail establishments well after eleven P.M. some of whom will be in school the next morning.

When I was a kid ( that was a few more than 20 years ago!), children in grade school typically had to go to bed around nine or ten o’clock. The conventional wisdom was that children needed between eight and ten hours of sleep per night. The older you got, you gradually got later bedtimes imposed—usually by the time you were a Senior in High School you were pretty much in synch with the adults as far as schedules were concerned,

I know, of course, that many adults work nights or have schedules vastly different from what they were 30 or more years ago, and whatever a family’s circumstances are, are certainly their own business. But school schedules haven’t changed much.

I’m just wondering if kids going to bed earlier than adults is some cultural norm that has faded into the past. It seems kids are up and even out in public whenever parents are up nowadays.