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.
Sometimes when I really get into something, I just stay late and work on it while the office is empty.
Thankfully I’ve been in positions where if I work the rare 10-12 hour day, I can take the time off later in that timesheet cycle. It helps that I always have a bunch of results to show after those nights.