Working Paper

Solar cycles and time allocation of children and adolescents

Published: 2024

Understanding how children allocate their time in response to daily solar cycles is crucial within the realm of child development research. This study investigates the time allocation patterns of children and adolescents, with a specific focus on sleep patterns, in relation to variation in daily solar cycles. We contribute to a substantial body of literature examining the interplay between solar cycles and sleep, as well as the emerging research exploring the impact of solar cycles on time allocation among adults and children.

Utilizing 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 significant correlation between daylight duration and sleep patterns. Our findings reveal that days with longer daylight hours are associated with a decrease in total sleep duration, driven primarily by later sleep onset and earlier wake times. 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 weekdays exerting a stronger influence on sleep duration, while children of mothers with lower education or unemployment exhibit a subtle impact.

In terms of policy implications, our results underscore the importance of considering environmental factors, such as daylight duration, in designing interventions aimed at promoting healthy sleep habits and overall well-being among children and adolescents. Policymakers and educators may need to adjust school schedules or recreational programs to account for variation in daylight length, particularly in regions where these fluctuations are more pronounced. Furthermore, our findings highlight the potential need for targeted interventions tailored to specific demographic groups, such as older individuals or children from socioeconomically disadvantaged backgrounds, to mitigate the adverse effects of longer daylight durations on sleep duration.


Nguyen, H.T., Zubrick, S.R., & Mitrou, F. (2024). ‘Solar cycles and time allocation of children and adolescents’, Life Course Centre Working Paper Series, 2024-07. Institute for Social Science Research, The University of Queensland. DOI: 10.14264/93cd9c0