Adolescent relationships to peers and friends are regarded as sources of social support and as a context for the development of social and emotional competencies. In the German land Brandenburg a sample of 380 students from 21 classrooms in 7 schools were questioned by questionnaires at the beginning and at the end of grade 7. The schools were organized in a way that students spent either half the day or the whole day in school. Data collection and analysis were based on the social competence model of Rose-Krasnor und Denham (2009). While the emotional competencies were assessed through adolescents’ self reports, social competencies were corroborated by classmates’ and teachers’ reports. While the prosocial orientation and the ability to solve social problems constructively did not change much during seventh grade, significant time effects were noticed in regard to adolescents’ social awareness, their self awareness and their self regulation. Students from all-day schools showed a significant increase in their attention to other peoples’ feelings, while this ability declined somewhat among students from half-day schools. In addition, physically aggressive behavior decreased among boys form all-day schools (and increased somewhat among boys from half-day schools). Boys from half-day schools were also the only group whose attention to their own feelings did not increase over the course of seventh grade. These results are in line with those of other studies. They are discussed from the perspective of the changing demands of the increasingly globalized world that the adolescents grow up to.