How does the sundial work?
A sundial is a device that measures time by the position of the Sun. The most commonly seen designs, such as the ‘ordinary’ or standard garden sundial, cast a shadow on a flat surface marked with the hours of the day. As the position of the sun changes, the time indicated by the shadow changes. However, sundials can be designed for any surface where a fixed object casts a predictable shadow. Most sundial designs indicate apparent solar time. Minor design variations can measure standard and daylight saving time, as well.
