Decan

What Are Decans?

Decans were a special way that ancient people, especially the ancient Egyptians, used groups of stars to tell time at night. They split the sky into 36 parts. Each part covered 10 degrees along the path the Sun follows, called the ecliptic. By watching which group of stars, or decan, was rising, people could know what time it was during the night. This was like a clock in the sky!

From Egypt to the World

The idea of decans started in Egypt a very long time ago. They used these star groups to divide the night into "hours" and the year into groups of ten days. Later, other places like Greece and India also used decans. In India, they called this way of splitting the sky the drekkana.

Fun Star Facts

Each decan had a group of stars and related gods. Together, the 36 decans made up 360 days, and the Egyptians added five extra days to match their year. Today, scientists are still curious about exactly where these special stars are in the sky. Decans were an important step in learning about the stars and keeping track of time.