The most common way to tell time without the use of a watch is by using the location of the sun. The location of the stars is another method, as is observing animal life.
Studying the sun’s movement across the sky and dividing its path from sunrise to sunset into equal sections is the most certain method for telling time, since the sun always rises in the east and sets in the west. For instance, if sunrise is at 6 a.m., and sunset is at 6 p.m., then the midpoint is 12 p.m. Halfway between sunrise, the midpoint is 9 a.m., and equidistant from the midpoint to sunset is 3 p.m. Using the stars to tell time is a little more difficult and only possible in the northern hemisphere.