All-day schools design compensatory figures for legitimization or as an orientation-effective foundation of meaning. These figures oscillate between the justification of a "holistic" school as a kind of "replacement family" on one hand, and the justification as a place of necessary optimization, namely extensive school learning, on the other hand. Some schools commit to high goals of a fundamental structural transformation of their historically developed learning and school culture. The requirements for legitimization are thus addressed through symbolic constructs of meaning. These represent one of the crucial frameworks for the development of learning and teaching culture in schools with all-day programs. The volume documents initial empirical research in educational science on all-day schools.