I know that bettas do best on a night and day schedule similar to humans, but (as I type this my toddler is screaming in the background), sometimes the only block of free time I have to do a full 100%, top to bottom, scrub everything, arrange, rearrange, re-rearrange (yes, I know, slightly ocd

), my 3 gallon tank, and then gradually reacquaint Himself to his new ph, temp, and fresh space is late at night, like around 11pm (like, get started then), sometimes later.
Could this be causing him stress by disrupting his normal cycle, with the added bonus of being in his tiny "holding pen" while I'm cleaning his abode? It's only once a week, but I feel bad when he is noticeably resting and I have to scoop him out and (ffrom the looks he gives me), piss him off royally.
50% changes (I usually do once a week, maybe twice if it's noticeable grungy), are easy and much less time consuming, and stress him out way less, if at all.
Thoughts? Theories? Opinions?
When do you change your water/attend to betta maintenance? When do you think is the best time of day (from the bettas' point of view) to do so?