Is productivity of the company based on employee’s happiness or working hours?

Well my 10 years of industry experience taught me a lesson which I feel is the key of success to any organization. The productivity of the company does not increase by the amount of work you do, but it increases by how efficiently you do. It does not increase by the working hours of the employee, instead it increases by the happiness of the employee. Happiness is the key to success in every aspect. If your employee is happy your productivity will double whether they work for 8 hours or not. I came across a post on Facebook a couple of weeks ago. There is a company in Germany which did a simple experiment for a couple of days and their productivity increased by 60 percent. They reduced the working hours and days to see if that made any difference. And their productivity increased to 60 percent because their employees were very happy with new timings, they became more productive ,more dedicated to their work. They used a very simple formula , they changed the working hours from 9-5 to 8-2 as morning time is always refreshing, people are energetic and focused. As the time moves our mind starts getting tired due to which we get slow in work which results in less productivity, so it's better to work till you start feeling lethargic. Even the science is also involved behind as post lunch our mind and body starts digesting the food which makes us feel sleepy and less focused due to which we are unable to work properly and unnecessarily consumes office stuff, so it's always better to work till lunch and go home and relax.