I’m pretty obsessive once I get going. I tend to throw everything at it, and I’m generally rather happy if I’m making progress of 450 to 500 words a day. I work from 9:30 in the morning. If things are going, I see no reason to stop, because I know there’s a point I’ll get to, a moment of hesitation, and a day or a week will pass before I see the way through.
Sometimes, I work late at night, sometimes into the early hours if things are going along. I spend a lot of time at the beginning of a day looking over things from the day before. I was a very early adopter of word processing back in the early ’80s. Being able to constantly correct is good for writers.
I think you do need to come away, somewhere along the line, and let it sit, so you can come back with a completely fresh eye and almost regard it as the work of a stranger.