Here in Radical we don't have "Casual Fridays" and that's because we have no Fridays at all. And the rest of the days are casual anyway. So, after trying out with this schedule for a couple of years, I can confidently say that it was a good decision. This concept was not originally our idea. I read about a startup (don't remember which) that did the same thing. That was my inspiration. What was original in our case though, is that we did the "4 days a week" thing while founding a company in the depressing economic environment of Greece.
Anyways, let me explain why I made that decision. I'll be very honest, I am not a workaholic, but I do work really hard and very long hours. For more than 10 years, I've sacrificed a lot of stuff for work. Having free weekends is something, but it's not enough for me in order to do all the stuff I love and still have time to spend with friends and family. The work of a programmer can get really unhealthy, both physically and mentally. So I thought, "if the week had 8 days instead of 7, what would I do? Would I choose to work the bonus day in order to be more productive, or would I choose to spend it on something else?". I immediately chose the latter. And that made a click inside me. The projects and the deadlines will never end. There will always be more work to be done. More hours to spend in the office. More tasks to squeeze from everything. But this is not the lifestyle, nor the culture I want to develop in my company.
So, free Fridays for everyone. We can still work hard Monday to Thursday and have a free Friday to go short vacations, learn a new language, do nothing, spend time with family, go shopping avoiding rush hour, etc. How did that affect our company? Well, I can't compare it with something else, but we are still open and profitable, and I can say without any doubt, that people are really happy with that schedule. And I mean, really happy. It makes a huge difference in the rhythm of our lives. Week days go by faster, and are not dull at all. And if we have to work some longer hours, we always know that there is going to be enough time to relax at the end of the week.
Maybe this schedule is not ideal or good for other companies or organizations. Maybe we are losing some money and productivity. But in our case it's the way to go.