At least for me doing meaningful hacking as part of my daytime consulting inspires me to work on my side projects in evening/during night instead of tiring me.

At least for me doing meaningful hacking as part of my daytime consulting inspires me to work on my side projects in evening/during night instead of tiring me. On the other hand day spent doing nothing of direct value (paperwork, useless meetings and so on) leads to evening spend by essentially doing nothing.