Introduction
This introductory chapter traces some of the major strands of social change thought to have had an impact on different areas of children's daily time use. The past several decades have witnessed rapid social, economic, and technological change, widely thought to have affected many aspects of children's daily lives. Technological change potentially has had the most direct impact on children's lives, and certainly has garnered the most attention, through changes affecting screen-based activities. Education is a further major domain in children's lives where there has been persistent change over many decades. The chapter then examines the relationship between children's time use and outcomes relating to their health, development, and well-being, drawing together strands of thought from the sociology of childhood and research on child well-being. It sets out the data, measures, and methods of the empirical analysis, followed by a first outline of change in a child's day over four decades between 1975 and 2015.