How Sundials Work

A sundial is a device which is used to tell the time of day using the sun’s light. Before the invention of clocks, our ancestors would rely on their sundials to figure out what time of day it was. Today, sundials are commonly used as outdoor ornaments and come in a variety of styles, colors and materials.  

Sundial Basics 

Almost every sundial comes with two basic components: a pointer, known as a style or gnomon, which casts a shadow on the dial, and a numbered dial on which the shadow will fall, showing the hour of day. When it comes to sundial varieties, the possibilities are almost endless. You can find sundials with flat or curved dials, and others which are vertical in order to display them on the sides of buildings. The flat, circular dial is one of the most commonly used types, and also makes for a pretty garden ornament. The style of this type of sundial points due North in the Northern Hemisphere to form an angle with the dial which is equal to the latitude of the sundial’s location. This ensures correct movement of the shadow across the dial in order to display the right time.  

How Sundials Indicate Time 

The time indicated by a sundial is solar time, which differs from standard time by varying amounts throughout the year. In order to determine the time shown by most sundials, you will need to use a variable correction method, known as the equation of time. Unless the sundial lies directly on a standard time meridian, it is also necessary to make a correction for longitude. Some sundials are designed to be read correctly in standard time, containing either a specially ruled or movable dial which must be periodically shifted throughout the year.  

How Accurate Are Sundials? 

The accuracy of a sundial will largely depend on its specific design. Some simple sundials are able to tell time that is only a few minutes in variation from the actual time, whereas others that are more carefully built and intricately detailed can manage to tell the time with a minute’s accuracy or even less.  

Sundial History 

The sundial is one of the oldest known instruments used for telling time. Although the origins of the sundial are uncertain, it is mentioned in the Old Testament of the Bible, and history suggests that it was used as a reliable method for telling time by the Ancient Greeks and Babylonians. Nearing the end of the Middle Ages, sundials were at their peak of popularity, with hundreds of different designs and models available. However, since the invention of clocks, the sundial has lost its use as a time-telling device, although some enthusiasts today still use them for this purpose. Today, it is merely used as a decorative accessory for gardens, yards and lawns.  

Sundials can make an interesting addition to any outdoor space, and can be fascinating to use. Sundials also make interesting, unusual gifts that can be given for an anniversary or any other special occasion. Give an Sundial as an anniversary gift made of your Anniversary Theme metal. Bronze, Copper, Brass and other metals are common materials found in Sundials as well as common Anniversary Themes.

Browse our store to find more like these:

Made in Brass

Made in Cast Iron