The longest I had, while being at home, was 10 weeks. Was an extreme situation with health issues and real life problems, where I didn’t touch it besides turning things on or off.
When life runs it’s normal course, I’d say 12 hours at most. Even on vacation I’m checking and doing things, that I found to have forgotten before I got on the road.
But, I have defined my end goal: my home should be so smart, that it can react on everything by itself, no matter I’m home or not. And I can say, I’m getting closer.
This year has brought some really cool things, that fit this goal perfectly. I can finally work with my tablets for voice in a usable way, I retired my Rhasspys (for now), Mushroom cards was a game changer for me in combination with the really cool themes from Madalena (= my dashboards finally look cool, imho) and all the other more “minor” changes.
If I had to pick a favorite, I’d say “Year of the voice”. I’m not used to talk to my home, so I find myself more often than I wanted doing things on a dashboard, but that will fade. And with a mic/speaker on nearly every corner of the house, it is more and more useful to just tell “Jarvis” what I want from him and what he should do.
So yeah, 12 hours at most seems a reasonable answer to your question