I worked for a very progressive company in the mid-80s that did 4 1/2 day work week, 7:30-5:30, and 7:30-11:30 with flex time options. Productivity was through the roof. We also experimented with other trends common today like open floor plans, shared office space, etc. and gave them up due to negative impact. Sadly, a new CEO and a sell off of a couple of divisions ended the practice, back to 8-5, no flex option, just like everyone else.