I need a solid 8 hours. Any time after 8pm is fair game and am usually up by 4ish. The alarm is set for 4:45 just in case, and there are times when it goes off. I was a rock sleeper prior to having children - in HS I had an old alarm that sounded like a freight train. I would set it in a canning pot to make it louder so I would hear it. There were still times my mom or dad would have to come in and wake me because it woke them up at the other end of the house. Once my kids were born, they could sigh and I would hear it.
There have been studies about artificial light and in its absence, it is/was common for humans to have 2 sleeps so awake for an hour or so in the middle of the night. This is proving true for both Hubby and me as we use less and less artificial light.
@Supervisor42 might try to limit screens for a certain period of time prior to "bedtime." Screens stimulate certain parts of your brain.
Also, I usually like winter (standard) time, but this year didn't sleep well most of those months. Since DST, have slept much better. I don't do changing of my routine very well.