In a recent Inc. article Nothing like a weak team or an unrealistic schedule to start a project off right, one of the mistakes that is often made is called work till midnight. It suggest that working more hours is not better for a project or an employee especially on software projects. The reason being is that many jobs require immense intellectual effort which can rarely be sustained for more than a few hours a day.
I agree with these thoughts. I have come to believe that is not how many hours you put in that determines your success or the success of a project but rather how you execute and focus while you are working on specific tasks. Whether it takes you 20 minutes or 2 hours to do something the only thing that should matter is the quality of the final product / result and if the goal was attained that was developed at the beginning of the assignment all parties should be happy.
I think to many people get tied up with regards to how many hours they are working as opposed to how productive they are during those hours and if you can be more productive during those hours you should be able to decrease them.