Table 2.

Spearman correlation coefficients between measured light exposure in the evening and at night and proxies of outdoor exposure ($n=256$).

Time frames of average LAN exposure	VIIRS-DNB	ISS photoa
Average bedroom exposure during the darkest period of the night ($n=250$)b	$-0.04$	0.02
Average exposure in the time children were reported to be in bedc	0.03	$-0.002$
Average exposure during the time period of civil twilightd	$-0.11$	$-0.03$
Average exposure between start of civil twilight and bedtime ($n=217$)e	$-0.05$	$-0.004$
Average exposure in the hour before children went to bed	0.04	0.007

Note: ISS, International Space Station; LAN, light at night; VIIRS-DNB, Visible and Infrared Imaging Radiometer Suite Day/Night band.

^aISS photo: composite photo from pictures taken from the ISS.

^bBetween 0012 and 0310 hours, corresponding to the start and end times of astronomical twilight (geometric center of the sun is 18° below the horizon) during the shortest night of the year, the lower n is based on six children for whom only measurements during the full moon were available.

^cBedtime: self-reported information from diaries.

^dCivil twilight corresponds to the time period when the geometric center of the sun is 6° below the horizon.

^eThe lower n is based on several children for whom bedtime preceded timing of civil twilight.