How did the Sumerians view the concept of time and how did they measure it?

The Sumerians, who lived in Mesopotamia around 4000 BCE, were one of the first civilizations to develop a system for measuring and keeping track of time. They viewed time as cyclical, with events repeating themselves in regular intervals. The passage of time was closely associated with the movement of celestial bodies, and the Sumerians believed that the gods controlled these movements. They divided the day into twelve parts, each corresponding to an hour, and the night into twelve parts as well.

The Sumerians developed several devices for measuring time, including the sundial, which used the position of the sun to determine the time of day, and the water clock, which used the flow of water to measure the passage of time. They also used lunar cycles to track longer periods of time, such as months and years. They based their calendar on the phases of the moon, which they divided into twelve months of 29 or 30 days each, with an extra month added periodically to keep the calendar in sync with the seasons.