The government in terms of state administration issued a number of policies to answer the challenges of education in terms of character development. The full day school system is one form of an educational model that is very supportive to improve the quality of education and develop student character values. The purpose of this study was to describe the strategy and application of full day school system learning in fostering the religious character of students at SDIT Bunayya Medan. This type of research is descriptive research with a qualitative approach, and researchers as the main instrument. This study uses data collection methods through observation, interviews, and documentation. From the results of research on the Application of the Full Day School System in shaping the religious character of students at SDIT Bunayya Medan, conclusions can be drawn that; 1) the application of a full day school system in fostering religious character students use varied learning strategies, such as fun methods, good classroom management based on school culture, 2) full day school implementation runs smoothly and can be accepted by students and parents of students well.