I beg to differ that it has nothing to do with navigation. What time it is directly effects the position of the sun or stars that you are using to navigate by. If you are following the sun, the position of the sun at 8am will be in a totally different direction that it would be at 5pm. So it would really help to read the signs (sun or stars) at the same time each time to keep your traveling direction consistent. So a sundial (till time pieces are researched and developed) will be one of the main ways of doing this. Another way is by compass if you have one which I am not sure you will start the game with one. Also a sextant for following the stars will be yet another method but the time and their position will be critical for a accurate reading.