Tracing Back the Origins of 24-Hour Days

Have you ever stopped to think about why we use 24-hour days? How did this timekeeping format come about? Interestingly enough, the concept of 24-hour days dates back thousands of years to the ancient Sumerians. In this blog post, we'll delve into the origins of 24-hour days and explore how the Sumerians paved the way for modern-day timekeeping.

The Sumerians were one of the earliest civilizations in human history, existing in Mesopotamia between 4000 and 1900 BCE. They were famous for their achievements in agriculture, urbanization, and writing, and also for their contributions to science and mathematics. One of their most notable accomplishments was developing a timekeeping system based on 60's and 24's that is still used today. This system enabled them to establish the year as having 360 days, broken down into twelve 30-day months, and further divided into 24-hour days.

The Sumerians' decision to use 24-hour days was based on their numerological system, which was based on 60's. The number 60 played a crucial role in Sumerian civilization. They used a sexagesimal, or base-60, system for counting and measuring time, which determined everything from the size of a circle to the way in which they told time. They divided an hour into 60 minutes and a minute into 60 seconds, making it easy for them to calculate and divide units of time.

The Sumerians' timekeeping system was adopted by several other cultures, including the Babylonians and the Egyptians. However, it wasn't until the 14th century that mechanical clocks were developed, enabling people to measure time more accurately. In the 16th century, the adoption of the Gregorian calendar standardized the length of the year to 365.24 days, and the length of every month was adjusted to either 30 or 31 days.

Despite the advancements in technology and calendar reform, the 24-hour day remains a fundamental part of modern life. This system allows us to structure our days and divide our time into manageable chunks, whether it's for work, rest, or leisure activities. It also allows us to coordinate with others across different time zones and cultures, helping to break down geographical barriers.


In conclusion, the origins of 24-hour days can be traced back to the ancient Sumerians. Their use of a sexagesimal numerological system, based on 60's and 24's, paved the way for modern-day timekeeping. While advancements in technology and calendar reform have improved our ability to measure time more accurately, the 24-hour day remains a ubiquitous part of our lives. Thanks to the Sumerians, we have a system in place that allows us to divide our day into manageable increments and coordinate with people across the globe.
Back to blog