Here's how it works:

* The Shadow: The sundial uses the shadow cast by a gnomon (a vertical rod or pointed piece of metal) to indicate the time.

* The Sun's Position: The position of the sun in the sky changes throughout the day, causing the shadow to move across the dial's markings.

* The Markings: The dial has markings that correspond to different hours of the day.

It's important to note that sundials are designed for a specific location and latitude. They won't accurately tell time in other locations.