I remember the Heroku founders espoused 6 hour work days for developers. They felt that this was the daily limit for creative workers - and that there was not o

I remember the Heroku founders espoused 6 hour work days for developers. They felt that this was the daily limit for creative workers - and that there was not only diminishing returns after 6 hours, but potentially negative ones (due to bad decisions made when overworked).