Sundials are devices that depict and measure time by the position of the sun. Sundials are considered to be one of the most popular weather instruments that denote time. The history of Sundials can be traced back to ancient Egypt. The “obelisks” and the shadow clocks from 3500 BC Egyptian civilization are the ancient forms of Sundials. These clocks were also very popular among the Greek, Chinese and Roman culture.

Theodosius, the famous mathematician and astronomer was the inventor of this magnificent concept of Sundials. His invention could be used anywhere on Earth and was known as the universal sundial . After Theodosius several other Astrologers around the globe started constructing sundials . In 1524 Oronce Fine, a French astronomer built an ivory sundials. An Italian astronomer Giovanni Padovani published a treatise on sundials which included instructions for manufacturing vertical sundials and horizontal sundials.

The time on a sundial is determined by the shadow cast on the surface. The ‘ordinary' or standard garden sundial s are designed in a very common pattern. These sundials cast a shadow on the flat surface with the hours of the day scripted on it. It changes according to the position of the sun. Sundials can also be designed in a different way where the shadow casting object should be fixed on any surface.

Over decades Sundials have undergone various development and advancements. Following are a range of types of sundials ever created:

•  Garden Sundial

•  Portable Sundial – Diptych sundial and Elevation sundial.

•  Precision Sundial (heliochronometers) – Reflection sundial, Analog calculating sundial, etc.