Does the United Nations work bad these days?

When did Saturday and Sunday become universally accepted as don't-go-to-work days in the United States and other Western nations?

• Answer:

  It goes back to when Constantine moved Rome, which used the 365-day Julian Calendar with 7 day weeks, into Christianity and they considered Sunday to be the Sabbath Day, so that became the official no-work day so the Roman citizens could pray and worship.  Much later on in the post-war era, long after the Roman Empire collapsed, many worker's rights advocates pushed to make Saturday a day off to go with the new concept of 40 hour, 5-day standard work weeks in the United States, one reason so that fathers could spend more time with their families and also so Jewish citizens would have their Sabbath day, which is on Saturday in their religion.