The two assumptions that aren't quite right are the number of characters per line and the number of hours per day. For most work it's hard to spend more than fo

The two assumptions that aren't quite right are the number of characters per line and the number of hours per day. For most work it's hard to spend more than four to six good hours per day just doing actual work; but when kicking tires on a hobby project, it is easily possible to stay engaged for an unhealthy amount of hours in a row.