I have been working 25 hour weeks for a little over a year now, but agonizing over finding a good number for years before that. I've found that for difficult problems to crack, I may only work 1 or 2 hours per day. But for easier stuff like initial setup, a little refactoring, translating wireframes to layouts, etc, I can easily manage 6 or 7 hours per day. 8+ is too much, and working 3 or more days in a row at that…
interesting