To join the several comments here: let him work on his startup part-time (20-40%) during work hours, as long as he gets his responsibilities done. I've quantifi

To join the several comments here: let him work on his startup part-time (20-40%) during work hours, as long as he gets his responsibilities done. I've quantified this idea a bit in a blog post: http://blog.ezlearnz.com/post/40316576/the-6-hour-workday http://blog.ezlearnz.com/post/40316576/the-6-hour-workday