Why do we divide our lives into 7-day chunks? Unlike the day, month or year, there’s no natural reason for this cycle, but nevertheless the week is now deeply ingrained in us and has proven very resistant to change. We explore the pagan, religious and early scientific roots of this man-made rhythm, the ideological battles fought over it, and the reason why the number seven came out on top. Our expert guests explain where the names of our days come from, why the weekend was born, and how the week has come to dominate our economic and social lives. There have, however, been several radical attempts to rip up the 7-day week – we hear about these alternatives and why they ultimately failed. Rajan Datar is joined by Eviatar Zerubavel, distinguished professor of sociology emeritus at Rutgers University, New Jersey, and author of ‘The Seven-Day Circle: The History and Meaning of the Week’; Ilaria Bultrighini, honorary research fellow in ancient history at University College London; and David Henkin, professor of history at the University of California, Berkeley, and author of ‘The Week: A History of the Unnatural Rhythms That Made Us Who We Are’. Producer: Simon Tulett (Picture: A signpost with the seven days of the week on the directional arrows against a bright blue cloudy sky. Credit: Getty Images)