Ever since I started freelancing 2 years ago I've been working about 2-4 hours a day of solid work. When it's crunch time I'll do 40-80+ hour weeks with 90% productivity (according to rescue time), but that's only for spurts 4 or 5 times a year.
Now I'm running an agency and finding myself needing to set expectation levels for employees, but if I did 40 hours of pure design everyday I think I'd feel burnt out.
I always looked at it like I needed the other 4 hours for research, education, reading, or fresh air because 8 pure hours of design didn't seem sustainable to me.
Freelancers and full-time designer's alike: What are your work hours? Do you think 8 hours of pure productivity 5 days a week is possible doing such creatively focused tasks?