The clock may be the earliest the sun, and time from sunlight at a disc angle of the projection changes the decision. Because of this method of measuring time originated in the northern hemisphere, observing time, people in the northern hemisphere, the sun rises from the east in the west, so the direction of movement of the shadow is what we now think in a clockwise direction. When the invention of mechanical watch out, the logical way it turned. And then later turning quartz also follow suit.