I just pulled up the last year's worth of consulting invoices and yes, it looks like I managed to bill an entire 40 hours once in the last 52 weeks. I have a personal policy of only billing for the time I'm creating value. So if I boot up, fire up the IDE, sip my coffee, pull up a bug report, then proceed to browse f'ng Hacker News for 2 hours, I don't charge my time. Similarly, if I notice by lunchtime that I'm just…
The only time I've been able to rack up more than 20~25 hours is when I work at the client's office (as I've been doing for the past couple of months).