> My preference for the night, I expect, has mostly to do with it being the time that I have the most peace of mind. There is something about daylight that makes me anxious. I can't really explain why.

This is what I expected, actually. At night you know that nothing is going to happen, nobody is going to call, and nobody is waiting for you to do anything, because they are sleeping. I wonder if this connection between anxiety and sleep patterns has been explored; not the usual "anxiety keeps you up at night", where you're lying in bed worrying, but "anxiety makes you want to stay up at night", where you're staying up and finally relaxing.