This report spotlights the many reasons why six-hour school days and nine-month school years were better suited to the nation's agrarian past than to the 21st century's demands and opportunities. U.S. schools are losing an estimated $21 billion each year because of summer learning loss among children from lower-income families. The report advocates adding more and higher quality learning time, with an emphasis on improved curriculum, more effective teaching, more enrichment activities, and better accountability.