Sundials

A sundial is an ancient timekeeping device that uses the position of the sun's shadow to indicate the time of day. It consists of a flat surface called a dial, marked with hour lines, and a central object called a gnomon that casts a shadow as the sun moves across the sky. As the sun shifts position, the shadow moves along the dial, pointing to the current hour. Sundials rely on Earth's rotation and the sun's apparent movement and are most accurate when correctly aligned with the Earth's axis. They provide a solar-based measure of time during daylight hours.