8-hour work-days date from 1914's Ford Motor Company. Is having a work day of 8-hours productive or counter-productive in our time?

8 hour working day model introduced in1914 and it's still being followed. I think people might have experimented less or higher working hours but still stick to8 hours.. At any rate, I think8 hour working model is the right one as the person will have8 hours of rest (sleep), remaining8 hours to deal with personal affairs (daily routine work, as well as spending time with family)..Even though the person works for8 hours (stays in office for8 hours), the real productivity is around6 hours (people take coffee breaks, social time with colleagues, etc)...

I would look at this from the angle of: "what are the alternatives"? I have never been a fan of12 on,12 off as to my mind there is no built in "relax" time, it's work - sleep - work. A3 x8 hour shift pattern provides more of a "buffer" between sleep and work! At this juncture it is of course personal preference, I am sure that, speaking personally, my productivity and concentration levels would be far higher if I was working an8 hour shift as opposed to12 hours. I have deliberately ruled out any work periods shorter than  8 hours as not being viable.

In the field of Teaching Profession:  Less working hours is more productive (A teacher require a sound home work)

In other cases: A matter of controversy--In my opinion it require modifications-- because there is substantial improvement in the proximity of basic human needs--eg.olden days :poor  transportation modes--power shortage...........many more.  Now you can cover most of things with your earnings..

A40 -45% improvement in working hours required--otherwise connectivity for the work remains a problem.--Generally over8 hours working time is counterproductive it seems  if physical exertion is involved. 

Eight  hours is a common stretch of time available for team work, coordination and joint effort for common objectives apart form self productivity which would vary from individual to individual depending upon their abilities and potential.

Still productive.

A project with tight deadlines need employees to do overtime. Comp Off is provided as per HR policy and statutory requirement against overtime. With stiff competetion and project deadlines in current globalized economy even8 hours are short.