Our dogs follow a natural diurnal schedule and keep me in a pretty honest circadian rhythm. They wake me in the morning twilight with tails wagging, because a sunrise walk is their expectation, as it is every day. Sure, I’ve trained them to listen and respond while off-leach, but they’ve trained me to get out of bed and get moving before the sun pops above the horizon.
It’s a symbiotic relationship - they get their daily activity and brain stimulation, and I get my low angle sunlight, triggering my cortisol bump which gets my internal systems moving appropriately.
In the winter, we sleep more and the early rises aren’t too bad. But in the summer, where at 46N latitude the sun rises at 5am, it’s a very early start! But, the advantage is that I’m following that natural rhythm too, which I rationalize as a helpful weapon against the constant advancement of technology in my life.