It has been tried before in Sweden, and it didn't work then either. It actually made workers sicker, and people were expected to do the same amount of work in less time.
Are you thinking about the change from 10 to 8 hours? Because that change seems to have been quite successful all over the world.
Regarding the 8 hour work day:
“One of the first businesses to implement this was the Ford Motor Company, in 1914, which not only cut the standard work day to eight hours, but also doubled their worker’s pay in the process. To the shock of many industries, this resulted in Ford’s productivity off of these same workers, but with fewer hours, actually increasing significantly and Ford’s profit margins doubled within two years. This encouraged other companies to adopt the shorter, eight hour work day as a standard for their employees.”
http://blog.bufferapp.com/optimal-work-time-how-long-should-...
