Figure 3.

Nighttime radiance. (A) Sleep duration by nighttime radiance. f = 10.017; P < 0.0001. (B) Bedtime hour by nighttime radiance. f = 172.985; P < 0.0001. (C) Wake up time by nighttime radiance. f = 29.102; P < 0.0001. Nighttime radiance was obtained using Defense Meteorological Satellite Program's Operational Linescan System light brightness from a 3 km × 3 km window over the geolocated address. The light brightness has been calculated based on the product called “Global Radiance Calibrated Nighttime Lights.” It composites acquisitions at high and low satellite gain.