For me (as a programmer) it really varies a ton. I used to put in insane stretches, due to the medication I needed to take in the past and that is how I got used to things in college.
Now I work more regularly, but still can put in a solid 6+ hr day most of the time, and yet some days… yeesh I’m lucky if I can get a third of that. So I work more on other days to compensate.
As a housewife, both 0 and 16? Since I don’t actually have a job, I feel like I’m not being productive if I am not cooking, cleaning or organizing. Try to make it so my spouse doesn’t have to do a single thing once she comes through, especially on her days off.