Daylight duration and time allocation of children and adolescents

Abstract

This study explores the allocation of time, particularly to sleep, among children and adolescents in response to daily daylight variation. Utilising a dataset of over 50,000 time-use diaries from two Australian cohorts spanning 16 years and employing an individual fixed effects estimator, we uncover a substantial causal impact of daily daylight duration on sleep patterns. Our findings reveal that days with longer daylight hours are associated with a decrease in total sleep duration, primarily driven by a later sleep onset time. Additionally, longer daylight hours correspond to reduced time spent on personal care and media activities, with increased dedication to school and physical activities. Furthermore, we identify socio-demographic factors moderating these effects, such as older age and weekend days exerting a stronger influence on sleep duration, while females and children of unemployed mothers exhibit a subtle impact. These insights contribute to our understanding of how environmental factors shape daily routines and offer implications for designing schedules that promote positive developmental outcomes in young individuals.