How to Tell Time With the Sun and Your Hand
The next time you are in the wilderness on a clear afternoon, try the following experiment: Place your hand between the sun and the horizon to get a rough-estimate of how many hours of daylight are left. This may sound a little over-simplistic, but this technique has been used since the dawn of camping, and the results are surprisingly accurate-- Most of the time.
How it Works
Position your hand so that the base on the pinky-side is parallel to the horizon. Each hand-width between the horizon and the position of the sun represents about an hour. Each finger space represents about 15 minutes. If the sun is three fingers up from the base of your hand, then you have around 45 minutes of daylight left. If the sun is three hand-widths above the horizon, then you have about 3 hours left.
Of course, specific times will vary based on the size of your hand and fingers. However, this will give you a good frame of reference as to when you should start heading back in order to reach your site or vehicle before dark.
Calibrating Your Hand Clock
The easiest way to find out exactly how much time the width of your hand represents is to compare your readings with a watch. All you need to do is divide the actual time by four, and this will give you a pretty close indication of how many minutes each finger represents. Once you have this baseline information, you can apply it to almost any situation in the field and get similar results.
While this method is far from perfect, it can be very useful in a number of different situations, particularly if you don't have a watch or can't read the time on your phone. The only real limitation to using this trick is that you need a good line of sight between the horizon and the position of the sun. You also need to be able to see the sun in the sky, which can be a challenge on cloudy days.
Despite these limitations, this is one little skill that you should practice, remember and share with others. Not only can you use this trick as a way to impress people with your vast knowledge of stellar navigation, but it may also prove to be helpful to someone in the course of their travels as well.