Whenever you are most energized. I’m a morning person so early morning works for me. I generally don’t want to do anything serious in the evening. But if you are a night owl then by all means, schedule your deep work at night.
Both works for me to be honest and also that it's only early morning & at night I really enjoy working on anything. My least favorite time for deep work is afternoon, because it's always a lazy feeling or too much heat at times, doesn't let me get the work done or well I don't enjoy doing it actually during afternoon. Evening is like to catch up on all things & dinner so not good either. The best is early morning till afternoon as it's a fresh morning a fresh start, without any thoughts or anything at all and late at night till dawn, because it's quiet and so at peace I love it, I actually love to catch at least a glimpse of dawn, it's the best.
Clearly in the morning, when your head is still fresh. You'll have more willpower and your brain has little residual 'noise' from all the other stuff that happened during the day.
It depends if you are an early bird or a night owl. So if you are usually more tired in the mornings then do it late at night and vise versa. But, if your nights are too busy, then wake up early and do it in the mornings.
I do all of my work at night but I would like to do it earlier. That is a very bad habit of mine, doing work very very late. It is a very bad habit of mine that I think fabulous could help me improve!!
I think it depends on what you are working on. I use deep work for things outside of my regular work day so I do it in the evening. At work though I get my best work done in the morning.
I prefer early morning and block time for this the first part of my day. In that way my energy is not sapped by random events and actions
The answer depends in your body and how best you operate. I am a lark and find that 2-3 hours after waking up is when I should do my hardest project.