The same for me (but 8 hour workday). Honestly, I couldn’t do the job if the working non-stop days were the default. I am wasted after such a high-stress day, so I need it to fluctuate. I also don’t feel bad on days where I do less, because I know I do a 110% on the other days. A workday is simply too long to be productive the whole time and the workload usually varies.