SCREENS: Sleep, Circadian Rhythms, and Electronics in the EveNing Study

Inclusion Criteria:

* children between 8.0 and 11.9 year old
* Tanner stage 1 and 2
* live with their parent(s) (biological or legal guardian at least 50% of the time and has a primary role of caring for the child).
* Children who sleep between 8.5 to 11 hours per night habitually
* Children must sleep alone most nights
* parent and child able to communicate and read and write in English
* The child does not have to have access to a mobile device (tablet or Phone), but if they do, the primary device they use has to be an a) Android OS ≥5.0 either used only by the study child or shared with others, b) Amazon Fire OS ≥5.0 that only the child uses or c) an Apple iOS ≥14.0 that only the child uses.
* If the child's primary device is a Android or Amazon Fired device, the parent and child agree to install Chronicle App (Android or Amazon). If the child's primary device is an Apple device, the parent and child agree to allow us to gather usage screenshots from the primary iPad or iPhone.
* Families must live in the greater Houston area.

Exclusion Criteria:

* child blindness or colorblindness
* significant vision problems
* developmental or cognitive delays
* diagnosis of a sleep or psychiatric disorder
* diagnosed cognitive or learning impairment affecting executive functioning (e.g., attention deficit hyperactivity disorder)
* medical conditions that impact sleep
* taking medications that impact sleep
* travel beyond 2 time zones in the month before starting the study