In many entrepreneurs I find that the dad/mom effect is real. When our first daughter was on her way, it made me kick things into high gear and that has allowed me to do what I like to do for fun during normal work hours.
I have pretty good energy and I attribute a ton of that to not having a commute. My office is on the 3rd floor of our house, so it's very separate.
In terms of time management, it really hasn't changed. I work generally 9-5 give or take an hour everyday and outside of that I'm pretty available. My wife and I are pretty good about not bluring the lines between work and play.
My wife is also a rock start at making life outside of work very enjoyable - when I get off it's less about house/life stress and more about enjoying our time together.