Call me entitled, but Why not just get up with the sun and go to bed with the sun. If the time of year makes "8" on a ticking device too early, maybe wake up a 8:22? Core hours make sense for businesses, but at the fringes we should just let it float.
Unfortunately with a partner, and being a light sleeper, it's simply not possible anymore. My bedtime is up to me, but my wake up time now has a hard ceiling.