condition mean min max 4 h after light 644.1 644.1 644.1 8 h after light 649.9 585.0 714.8 12 h after light 592.8 517.9 667.7 4 h after dark 696.2 579.5 812.9 8 h after dark 821.3 795.1 847.5 12 h after dark 718.7 597.2 840.2