Sundials are an ancient form of measuring time by relying on the position of the sun and the shadow that it casts. In many gardens, sundials are also used as decorative pieces. Some are large, heavy models that can withstand wind and other harsh elements, and others are small enough to nestle among garden flowers. If positioned properly, a horizontal sundial can accurately tell the time of day outdoors by using the sun's predictable pattern of rising and setting.
Place the sundial on a level area of ground. Position it where it will not be in the shade of large plants or trees and will be in sunlight throughout the day.
Point the style on the sundial to due north. The style is the triangular-shaped part of the sundial that sits vertically in the center. "Due north" is the point that is at zero or 360 degrees.
Watch as the sun moves across the sky to see the shadow that the style casts. It will move clockwise along the face of the sundial and casts a shadow on the lines that mark the time of day.
Adjust your reading of the time by one hour depending on whether the sundial was set during daylight savings time or standard time.
- When the sundial faces due north, the style will cast no shadow at noon.
- Since the sundial is circular and the earth is more elliptical, the time on the sundial would not be completely accurate.
- Shorter daylight days in winter will create weaker shadows on the sundial.
- Consider the time of year when the sundial was set when reading the time. If the sundial was set during standard time, the reading on the sundial will be one hour behind the time set on your clocks during daylight savings time. If the sundial is not stationary, reposition it to adjust the time.