When the bell rings at the end of a school day, millions of children are left to their own devices while they wait for their families to return home at the end of the work day. Findings from a study conducted by the Afterschool Alliance, "America After 3PM," show that 15.1 million children are unsupervised when the school day ends. The out-of-school time hours represent a challenge to families and community members who are looking for safe places and engaging activities for children and youth. The out-of-school time hours also represent a genuine opportunity for municipal leaders--the opportunity to rally the entire community around the goals of keeping children and youth safe and engaged, while also helping to advance a number of other key city priorities. City officials are well positioned to support the development of strong partnerships with key sectors of the community to increase the number and quality of out-of-school time programs. This guide highlights three key strategies that mayors and other city leaders can use to promote partnerships and build public will in support of out-of-school time programs. (Contains 2 footnotes and 14 resources.)