Working more does not always equate to working better or higher results. One of the best pieces of advice I’ve ever received was while working for The Ohio State University in which human resources during training shared that if someone tells you they need something right away, it can usually wait 24 to 48 hours. So unless you have one of those jobs that requires you be on call for true emergencies, such as fire or police personnel, you need to tune out work on your day(s) off. Not only does tuning out work benefit you, it benefits the organization you work for as well.
Need further proof? Below is an interesting quote from an in interesting article.
“The Greeks are some of the most hardworking in the OECD, putting in over 2,000 hours a year on average. Germans, on the other hand, are comparative slackers, working about 1,400 hours each year. But German productivity is about 70% higher.”-Source: http://www.economist.com/blogs/freeexchange/2013/09/working-hours