Now I wake up by 7 before my alarm even rings.
All it took was getting into the habit of trying to get a little person to sleep by 10 in the evening and falling asleep with them.
I'm still at my most productive at the end of the working day however and early morning is still not great.
I've tried to stick with this program, or at least a version of it, but ironically it's kind of harder now that there are two of us again.
This.
I regualrly slept between 1-3am for many years. After having a baby (6 month old), I'm ready to sleep whenever, and definitely can't stay up past 11. Huge win in terms of sleeping early and waking up early.
Have a baby. Fix your schedule.
But my point still stands, I can adhere to my new schedule pretty effortlessly when the situation is right. Which makes me personally question how much of being a night person is nurture.
Most of the night persons I've encountered have a pretty consistent schedule of staying up at night, which isn't what should be happening if they fit the profile of the kind of person that the linked study examines. A person like that should have, when situations allow, no schedule because they function on a non-24-hour cycle.
It made me realise that it's all just a number. In other words if you don't like getting up early, then go to bed an hour or two earlier. It has exactly the same effect. In countries with daylight savings we adjust our schedules by an hour two times year and no one makes much of a big deal. Its the same as that!
Now with a baby I'm usually sleeping by 10 and up at or before 6. I kind of like it though. Now the before-lunch period is the productive time.
There is no job, hobby, or other calling that could turn me into an early riser like raising children.
[Father's testosterone levels drop considerably starting a little prior to birth of their children (and when taking on care of young children) reportedly. Mother's hormonal changes go without saying, I feel.]
Just FWIW none of my well-spaced in age children fixed me. But having a fluid sleep cycle often meant I wasn't bothered. Sometimes I'm super awake at 4am, sometimes 6am, sometimes I'm ready to crash by 4pm, sometimes by midnight.
What killed me was having to work a second job during the night-time with our first kid, not fun.
In short, still broken sleep cycle, almost exactly like my mother has been through her life AFAICT.