This is me as well. My brain is useless until close to lunch time. After lunch I start feeling productive and this feeling begins to steamroll into the evening. When I am allowed to structure my day I don't even plan to start work until 6pm and can maintain great focus from then until 1am. Admittedly I imagine my ADHD has much to do with that and the habits I formed to cope with it as a child.

Interesting. My productivity ends after lunch! It's all downhill from there - lack of focus, easily distracted, silly mistakes, is-it-5pm-yet thoughts etc.

I think it is breaking for lunch that does it. When I didn't have any team mates in my office and I'd just eat at my desk I'd still get good work done after eating. Now I have team mates in the same office as me and we go for a "proper" lunch break - something about stopping and then having to go back to work I guess.

https://www.newscientist.com/article/dn24292-first-physical-... perhaps.

I also seem to wake up around sunset. Am also ADHD.

Same here. If I start early (particularly due to a meeting), it's difficult to do any serious mental work for the rest of the day because I consistently forget what I'm working on. I can force myself to work anyway, but then I'm more prone to make mistakes. It's much better for me to ease into work.

I learned a few years ago that defying my internal clock even has physical effects such as poor digestion and terrible stomach pain. The popular advice to rise early is harmful in my case.

Same here. I have always wondered how people can even wake up at 5 am, let alone focus and work.

In the mean time, I think, need for sleep is like appetite: some have more, some have less.

Waking up at 5 am doesn't imply sleeping any less (just going to bed earlier).

In the similar way, taking a nap doesn't mean that you sleep more, just that you schedule your sleep differently.