Sundials, which decorate church walls, public plazas, and elegant gardens, are first and foremost astronomical instruments. Before understanding how sundials work, one must first understand the apparent motion of the Sun in the sky. In this book, Denis Savoie presents the basics of astronomy required to understand sundials and describes how to design and build your own classical sundial. Written for all levels of science readers, the author shows the calculations involved in the sundial's construction and also gives a comprehensive history of time measurement. The practical and observational aspects of sundials will enable readers to create custom-made sundial of their own, adding whatever special features they wish to include. Most of these designs have been tested by people with no previous knowledge of astronomy. To aid the reader, the book is full of clear and instructive illustrations and diagrams.