I used to work a salaried job where I was required to log my hours, and the hours had to add up to 40 or 45 hours a week, or we'd be told we weren't working hard enough. I'd make sure I was in the office for that long, and logging all that time, but of course, it wasn't all productive.

More recently, I worked some other jobs where was payed hourly, and where the hours I logged would be billed to clients directly. I didn't want to overcharge, so I was always sure to stop the clock whenever I wasn't actively doing valuable work. And what I found was that I could barely do 4.5 or 5 hours before feeling totally burned out at the end of the day. This was doing computer / programming work.

Now, I work a salaried job from home, and don't have to log my hours. But I've continued logging my hours just for my own sake. And what I've found is that my average is about 3 hours a day. And it's fine. Everybody is very happy with my work, and I'm happy with my work / life balance.

But of course, I'd be worried about sharing that information with my employer, because they'd probably be stuck in the past, and wouldn't realize that in fact, I am working about as hard as I can without feeling burnt out.