I have no problems with working 12 hours a day for a short time, but I would never do it over a longer time period. A work day should not exceed 8 hours (lunch not included) in my opinion. I actually find my work interesting and enjoy working there, but I need to keep my work life and personal life separate.<p>Life is short enough as it is, so I don't want to spend 50% of it at work (more if you count the hours you spend sleeping). After a week of working "overtime", I feel mentally exhausted. It completely ruins my Saturday, so that's more of my life that is wasted.<p>I do have some pet projects that I work on sometimes. Even if I could integrate it into my work, I won't do it unless it directly affects my work. My work ethic is strong, and I always look for ways to improve the systems during work hours. But there is a limit to what I will do.<p>If my ideas does not interest my work place enough to include them in my work schedule, I will use them in my side projects. Giving away free overtime to solve problems that my work doesn't think is worth paying me for is not an option.