Not the person you asked, but, ADHD/ADD covers quite a lot, and what works for some might have adverse effect for others. It's not uncommon to be extremely focused and productive on certain tasks, then struggle immensely with distractions and procrastination for other tasks. I say immensely, because this applies to some degree to everyone.
I too felt I was only productive during certain times and deadzones. But, it turns out, I just need to be left alone to focus. Which not only means not being disturbed by others, but also not so easily doing it myself by wanting to interact with others. If no one else is working, nothing to do but focus. This same effect made working in an office exhausting.
I now work 40%, exclusively remote, and I get more done than I did at 100%. Some weeks by a factor of 2. "How is that possible?", consider that under normal office hours, I would clock in-the-zone productive work to about 2-4 hours. Remote: 7-11 hours. A bad week at the office: 10 hours, two good days at home: 20 hours.
"Yeah, but that's just you sucking at working in an office environment". Indeed. And there are dozens of us. Dozens! A good manager should strive to get the best value out of their workers.