>Combine this with a sense of how quickly the sun moves, and you can work out useful light after dark fairly easily. The sun moves through about 15 degrees of arc in an hour, and there are discernible amounts of useful light up to at least 18 degrees of arc below the horizon, sometimes more depending on weather -- and you can have well in excess of an hour before/after the sun is visible. Perhaps two hours or even more. And if the area has an open tree canopy, stars provide a fair amount of light if they are visible.

It is surprising to us city folks like me how much one can see by starlight alone. I have done a fair amount of camping in the California deserts, and it is amazing how bright a moonless starlit night can be. Several times I have been able to walk along a dirt road by starlight alone. About 3am, your eyes are used to the dark, you cannot make out any clear features but there are no trees, the ground is relatively light colored and while it would be dangerous to walk cross country, I have done it on a dirt desert road at night. It was BLM land where you can camp and find spots with no other people for miles around. On other moonlit nights I have read a newspaper inside my tent after my eyes were used to the dark. I imagine that people in days when there was very little artificial light, and where they had grown up and were used to these conditions and their surroundings, could do quite well at night. And most nights have at least some moonlight. I learned this quite early when our former Marine, Boy Scout leader made us leave our flashlights back in camp and took us on night hikes, navigating by moonlight alone. Along the way he would stop and tell scary stories. But that was ages ago. Fear of lawsuits would probably prohibit this kind of thing today.