Sundial made of two sandstone rocks perched on one another.

Before modern clocks, the movement of the sun across the sky was used to measure the passing of time. Today, sundials can remind us of what that number on a clock really means. In this sundial, the shadow-casting stone, called a gnomon stone, is angled to point directly at the North Star. To use this clock, look at the southern edge of the gnomon’s shadow (the trailing edge in the morning and the leading edge in the afternoon) and figure out the “sun time” along the hour markers. The first line, perpendicular to the gnomon stone, marks six o’clock. Since the sundial is not directly in the center of our time zone, add approximately 30 minutes to the sun time. During Daylight Saving Time (March to November), add one more hour.