A Trimester Schedule that Works is a guidebook for secondary educators who want to maximize teaching and learning opportunities in their schools. The book begins with research that supports a trimester schedule and then begins to help readers understand the change efforts and challenges associated with the redesign of the school day. Several planning tools are included to lead readers through the steps necessary to build the capacity for change and a culture of collaboration. The benefits of the improved schedule are then quickly divulged by the authors – increased time for core content classes, a bonus period for intervention and acceleration activities, opportunities for dual college/vocational education credit, to name a few. Several case studies illustrate how middle and high schools have transformed traditional settings into thriving, high-performing schools, with collaborative teachers and engaged students.