I have to again give credit to 37signals. In their book Rework, they pointed out the 800 pound gorilla in the room, over and over again. This video is a "gorilla" I've been dealing with for the last 15 years. I usually arrive at the office around 06:30 or 07:00 (2 hours before anyone else). Why? I'll probably get more done in those 2 first hours than I will the rest of the day. Though I only check my email at the top of each hour, I still deal with meetings and people "dropping by" to ask me questions or to tell me about the newest restaurant in their neighborhood. Interruptions mean you don't get work done. I'm not saying you shouldn't make your customer happy. I'm saying you should be able to get it done without working late.
Tell me if this sounds familiar. Some of your co-workers show up at the office around 09:00 (closer to 09:30) and then take a 1.5 to 2 hour lunch break. They then don't understand why you turn down meeting requests scheduled for late in the afternoon or don't respond to emails sent to you after business hours. Just because someone is unable to manage his or her work, I am not going to feel guilty for not working late. Before I had a family or understood work-life balance, I didn't hesitate pulling an all-nighter at the office. Now it just looks like poor time management.
So, are you working late tonight? Do you really have work you need to do are are you just trying to make yourself feel better by creating work for yourself? I'll make you a deal. Drink your preferred caffeinated beverage around 05:00 and get to the office no later than 07:00. You'll probably have the most productive day you've had in months.