[ScottBurson]

I mostly agree, but staring off into space can definitely be billable time. In fact, I think even time spent off-task can be billable, at least partially, as the brain needs time to digest what it has been presented with; I frequently find a short break can get me unstuck on a problem.

I think Patrick McKenzie recommends contractors bill by the day instead of the hour, partly to get them to consider necessary break time as billable. Of course, if you get to the end of a day and realize you really have been very distracted all day, you don't have to bill it as a full day.

Family distractions can be a big problem, though. You have to have blocks of several hours — I think the ideal might be two 3-hour blocks in a day — where you know you're not going to be interrupted, short of a true screaming emergency. Getting this across even to one's spouse, never mind a young child, can be very difficult. Getting out of the house might be the only way. As Paul Graham once observed [0], even the prospect of an interruption can be enough to keep one from getting into a flow state.

[0] http://www.paulgraham.com/makersschedule.html

[_sdegutis]

This is where I get stuck actually. I try to digest some information, but then I start worrying that I'm taking unreasonably long, that my client is definitely going to ask for a justification for why something that should have only taken 1 hour ended up taking 3 hours (because it could take him 1 hour or even less), and I won't have a good answer.

[ScottBurson]

Does the client actually ask for such a justification?

Anyway, let's say that you're right: something that would have taken him only 1 hour takes you 3 hours, because you're still learning about the code. I can tell you, speaking as someone whose time is valuable and who has to delegate tasks to people who don't know the code as well as I do, that I know it's going to take them longer, but it's an investment we have to make to get more people up to speed.

I understand that in your circumstances, "relax a little" is not easy advice to take, but it might be the best advice I can give you — along with making sure you have enough uninterrupted work time. It does sound like you need to get out of the house.