My parents were strict about bedtimes and curfews: 8 in gradeschool, 9 in middle school, 10 in high school. When we were driving/dating, we were allowed to go out one night each weekend (Friday or Saturday, not Sunday because that was a school night), and stay out till midnight. Prom night was the only night with a later curfew.
My kids had a bedtime in gradeschool, but not really after that. Our son would often go to bed before DH and I. Our daughter is a night owl, she'd go to her room when we went to bed, but would stay up for hours reading before she settled down. They never really had a curfew when out with friends, they would tell us when they expected to be home, and would update if plans changed. They were typically home by midnight anyway. They knew if they abused it, their freedom would have disappeared.