It's hard, damn hard. For a quite a while I was lucky enough to have a very boring, mundane, easy $DAYJOB where I could go in, slog through fixing a couple of bugs, and go home, retaining most of my creative, emotional, and intellectual energy for the startup. By my current $DAYJOB is a lot different... more challenging, but also more fun. But it really makes it hard to balance things.<p>I wish I could say I had some real solid advice for you, but all I can really do is share some anecdotes in the hope that you can glean something useful from that.<p>Basically, I try to compartmentalize my thinking as much as I can. During the day, at the 9-5, I <i>mostly</i> try not to let myself get drawn into thinking about "startup stuff", except during lunch. I treat lunch time as "startup time" and I often leave the office, go to a restaurant or coffee shop, and do startup work for an hour there. The delineation isn't perfect though, as I do keep a browser tab open all the time, with Gmail for my startup email address, and I do answer and send a few emails or whatever, throughout the day.<p>I might also, rarely, pop into the wiki for the startup and make a few notes about an idea that occurred to me, or a link I found or something.<p>Then, after work at the $DAYJOB, I immediately go back into "startup mode" most evenings. I leave the office, drive to a Barnes & Noble or something, sit in the cafe with my laptop and get back to work. Since I know I have "startup time" built into the evenings, it reduces <i>some</i> of the temptation to think startup stuff while I'm supposed to be working.<p>Now the fortunate thing is, my $DAYJOB employer knows about the startup, is an entrepreneur himself and is generally supportive. As long as I'm getting my work done and not letting things slip, he doesn't mind if I leave work early on occasion, or take a long lunch now and then, to have a meeting related to the startup, or whatever. I will also sometimes just flat out take a vacation day, to accommodate the need to do something for the startup.<p>I also allocate almost 100% of my weekend time to working on the startup. So the toughest day to stay focused can be Friday, since I'm mentally preparing to shift gears into startup mode for the weekend, and as Friday winds down, I might start drifting that way a bit. Luckily, Friday afternoons here are usually pretty relaxed.<p>The toughest part, really, is dealing with meetings during the day. Writing code, market research, writing, etc. I can do anytime. But meeting potential customers, investors, partners, etc., is a challenge since my daytime availability is somewhat limited. Basically I just try to schedule meetings for either A. over lunch (and just take a slightly long lunch), B. as early as possible in the morning (so that, at worst, I come in a little late), or B. as late in the evening as possible.<p>It's tough to balance both, but it can be done...