I work 7-hour days, but I might work 2 or 3 hours during that time. A lot of the time I find the work unbearable and can only bring myself to do it in short intervals. When the task is interesting, involves my skills, and I'm making progress, I can work for hours with almost no breaks. It really is an emotional thing. I won't force myself to do anything that is really painful because it ruins my mood for the whole da…
instead of slacking trough 8hours per day with an effective 2-3 hours of work for 5 days I take the 1 day(and/or night) were I work full concentration until exhausted (with small breaks) and take next day "off" (I'm connected still reachable in communication tools) to do personal stuff, side projects, watch TV, exercise, or just chores.
My overall productivity and mood are much better than when I was working from the office, but I'm afraid it's soon coming to an end unless I find a new job that's Ok with being remote.