If I have a few minutes here or there at work, I'll check chiefdelphi. If it's an easy answer, I'll answer it when I read it. If it's harder, I'll leave it until after work and usually someone else will have answered
. I also check for a few minutes in the morning and the evening.
I looked at the 50 people with the highest reputation. Most post less then once a day, and very few post more then twice a day. See the attached histogram. It may seem like some people are always posting, but looks can be deceiving.