First, I'd point out that there is a lot more acceptance now for "day rate" or "week rate." You can find its advocates in most contracting-related threads here on HN. If you are paid by the day, it doesn't matter if that's a 10-hour day or a 4-hour day as long as the client doesn't feel taken advantage of.
Nor should you be taken advantage of: I have friends in other industries where "day rate" is the standard, and it's a high rate but it sure does involve crazy hours when the project is in full swing. Ask a film editor about "work hours" and they will either laugh, or cry. Let's not normalize the 18-hour day!
Second, you should feel good about even worrying about this: it means you've got some ethics. But you shouldn't feel like you owe "flow state" for every hour you bill. Do you need to take a walk to clear your head and better concentrate on the problem? That's work. Lunch isn't that much harder: is it a working lunch? Bill it. Are you having a nice long lunch in order to not think about work, or maybe meeting friends? Don't bill it. (Day/etc. Rate obviates this problem.)
Third, socializing with the staff is a little complicated if you're billing hourly, or sometimes even daily. I would be pretty happy if a contractor went out for social food/drinks with my employees, but I would much prefer to pay for that in good will than in actual billed hours. On the other hand, if you're at one of those places with ping-pong tables and the SRE peeps really want you to play with them: bill it!
Nor should you be taken advantage of: I have friends in other industries where "day rate" is the standard, and it's a high rate but it sure does involve crazy hours when the project is in full swing. Ask a film editor about "work hours" and they will either laugh, or cry. Let's not normalize the 18-hour day!
Second, you should feel good about even worrying about this: it means you've got some ethics. But you shouldn't feel like you owe "flow state" for every hour you bill. Do you need to take a walk to clear your head and better concentrate on the problem? That's work. Lunch isn't that much harder: is it a working lunch? Bill it. Are you having a nice long lunch in order to not think about work, or maybe meeting friends? Don't bill it. (Day/etc. Rate obviates this problem.)
Third, socializing with the staff is a little complicated if you're billing hourly, or sometimes even daily. I would be pretty happy if a contractor went out for social food/drinks with my employees, but I would much prefer to pay for that in good will than in actual billed hours. On the other hand, if you're at one of those places with ping-pong tables and the SRE peeps really want you to play with them: bill it!