condition mean min max 4 h after light 6.772295 6.46327 7.08132 8 h after light 8.634855 7.92708 9.34263 12 h after light 10.6644 10.1896 11.1392 4 h after dark 11.1347 10.9321 11.3373 8 h after dark 9.830805 9.67602 9.98559 12 h after dark 9.73817 9.16614 10.3102