condition mean min max 4 h after light 8.139205 7.48967 8.78874 8 h after light 2.42443 2.16342 2.68544 12 h after light 2.40082 1.96609 2.83555 4 h after dark 7.971005 7.94217 7.99984 8 h after dark 9.03902 8.11382 9.96422 12 h after dark 9.155125 8.75061 9.55964