I'm a lark, always been a lark. When I was working full time I was up at 5am to drive to the rented fields to do animals before work and was almost always in by 8am to avoid the traffic, get parked conveniently, and be well underway before the 9-5 started. I was in bed by 10pm other than brief periods in life where I had a social life, but they were brief!
Now I have problems getting to sleep when anxious or overstimulated, problems staying asleep in the early hours (often needing to get up and go to the bathroom or wander about the garden before I can settle again) and I'm still usually up around 6, no later than 730 if I've been awake 3+ hours during the night.
Summer is hard as I also struggle to get to sleep at all when it's daylight outside - I keep saying I must get blackout curtains but there is always something more urgently needed when I have any spare cash! I'm fine with overnight foaling checks for a few nights, but getting up every hour or so for a sick one for 3 weeks had me pretty shattered, just as well I don't have a day job any more but I also fall into bed at 830pm in winter if I need to, no pride left where sleep opportunities in darkness are concerned!