The success of the four-day work week. Januszeksy in shock

I read in the press that “the results of the UK tests amazed experts. It's a four-day week. As many as 89 percent of the companies that took part in the test remained on this solution." Come on! I think it surprised, but mostly experts of the Polish School of Management. What are the circumstantial effects of the study? He wrote about it on X/Twitter Andrzej Kubisiak from the Polish Institute...