People who have projects, ventures or businesses outside their normal 9 to 5 jobs have to climb a daily hill called fatigue. It becomes difficult after a full day of "normal" work to push on with your personal (but important) interests. If you stay up late you're exhausted the next day - sleep deprivation is short sighted and isn't the answer.
Consider doing some before-hours work. Carla White created an iPhone application called the Gratitude Journal during the hours of 5 a.m. to 7 a.m. before going to her day job. Her initial morning efforts have now turned into a full-time career for her.
I used to have the same problem: the only time I made any decent progress was on weekends, 2 out of 7 days in the week. I was often too tired and very unproductive after getting home from my "normal" job. However by waking up half an hour earlier on weekdays with a fresh mind and the beautiful silence of dawn as company, I started achieving a great amount before proceeding with the routine parts of the day. This is the time for creative, higher order thinking. The rest of the world is still sleeping and now you have your time all to yourself. Just 30 solid minutes can yield immense progress.
So don't think that after-hours is the only time you can work; you should try to do a brief early morning stint to reduce the after-hour work. This also frees up more time on the weekend (if you're working this hard you will probably use your weekend to sleep in).
I believe the morning to be the best session for most because you’re at your freshest mentally; importantly your head hasn’t been filled with the usual cacophony of noise, information and stimulus that a typical modern day human faces daily. Your brain is tired at the end of a weekday because it is hard pressed to process all the things it has been exposed to during the course of that day. Not all hours are equal and you are very likely to achieve much more in a fresh morning hour than a tired evening hour. So here's the trade-off: go to bed earlier and wake up earlier. Reduce television time and Internet browsing in the night and climbing into bed by about 9 or 9:30 p.m. is far from impossible.
Remember you can and probably still will work in the evening; it's just a good idea to split your tasks between dawn and dusk. Important work must be done when your slate is clean and pencil sharp, the rest can be done after sunset.
The Happy Uprising is available on Kindle for $2.99 (prices may vary by region).Amazon Review: "This is a well written, smart and happy book about getting oneself out of the ruts we often find ourselves in - not only in the job market but also in life."