condition mean min max 4 h after light 10.041525 8.63105 11.452 8 h after light 13.2125 12.8619 13.5631 12 h after light 17.0325 15.6056 18.4594 4 h after dark 19.9418 19.7116 20.172 8 h after dark 16.0704 14.8746 17.2662 12 h after dark 15.52105 15.0286 16.0135