Mayor Walsh and Boston Teachers Union President Richard Stutman today announced agreement on a plan to add 40 minutes to the school day at the 60 elementary and middle schools in Boston that don't already have them.

Walsh said the move is a major step to ensuring "a world-class education for every student in the city." He said experience elsewhere and in Boston schools that already have longer days, such as the Trotter and Orchard Garden, show the extra time translates into better test scores, better educations and better beginnings for life.