Many young people do not get the sleep they need. Two-thirds of Danish ninth-grade students sleep less than the recommended eight hours per night, and many experience tiredness during the school day. At the same time, adolescents' biological circadian rhythms shift during puberty, making it more difficult to fall asleep early and wake up early. Insufficient sleep can affect physical and mental health, learning, well-being, and social relationships. International research suggests that later school start times may increase sleep duration and improve well-being and school engagement. However, most studies have been conducted in the United States, where the school day often starts earlier than in Denmark. Consequently, there is a lack of knowledge about how later school start times are planned, implemented, and function within a Danish school context, as well as which factors are critical for achieving the intended benefits.
Purpose
The project aims to generate new knowledge about the feasibility, implementation, and potential impact of later school start times in Danish schools. The purpose is to examine how the introduction of later start times is planned, decided upon, and implemented, as well as the experiences of school leaders, teachers, students, parents, and municipal stakeholders with this change. The project will also investigate the organisational and practical factors that support implementation, how students use the additional time in the morning, and the potential effects of later start times on sleep, well-being, and school life. The findings will provide the basis for an overall assessment of whether later school start times are a feasible intervention in the Danish school context and whether there is sufficient justification for conducting a subsequent effectiveness study.
Method
The project adopts a mixed-methods approach. First, a nationwide survey of school principals will be conducted to map the prevalence of later school start times and schools’ experiences with their implementation. This will be followed by interviews with school leaders, teachers, students, parents, and municipal stakeholders to explore decision-making processes, implementation experiences, and perceived consequences. Finally, workshops will be held with young people and professionals to translate knowledge and experiences into recommendations for supportive implementation strategies.
The findings will be integrated into an overall assessment of feasibility and implementation, as well as the potential for conducting a subsequent effectiveness study and informing future initiatives.
Project period
19.10.2026 - 31.12.2028
Collaboration and funding
The project is conducted in collaboration with the Center for Clinical Research and Prevention (CKFF). The project is led by Susan Andersen, head of research and senior researcher at SIF. The research team also includes associate professor Dina Danielsen from SIF. From CKFF, Christina Bjørk Petersen, senior researcher and associate professor, participates as co-project lead, alongside postdoctoral researcher Nina Kamstrup-Larsen.
The project is also carried out in collaboration with Just Human and Gentofte Municipality, which provide expertise and practical insights into adolescent sleep and the implementation of later school start times.
TrygFonden