condition mean min max 4 h after light 6.112905 5.1635 7.06231 8 h after light 7.717035 7.52879 7.90528 12 h after light 10.79805 10.6356 10.9605 4 h after dark 16.0646 15.3665 16.7627 8 h after dark 16.18125 15.7556 16.6069 12 h after dark 12.2079 11.8635 12.5523