The concept of counting years can be traced back to ancient civilizations and their methods of tracking time. One of the earliest known examples of humans counting years is the use of lunar calendars by various cultures.
The ancient Egyptians are credited with one of the earliest recorded attempts at a solar calendar, which was based on the annual rising of the star Sirius, known as the heliacal rising of Sirius. This event roughly coincided with the annual flooding of the Nile River, an essential event for their agricultural society. The Egyptians began using this calendar as early as 2700 BCE, making it one of the oldest known attempts to track the passing of years.
Similarly, the ancient Sumerians of Mesopotamia (modern-day Iraq) developed their own lunar calendar around 2100 BCE. Their calendar consisted of 12 lunar months, totaling approximately 354 days. To make up for the difference between this lunar year and the solar year, they occasionally inserted an additional month to synchronize the calendar with the seasons.
Other ancient civilizations, such as the Babylonians, Greeks, and Chinese, also developed their calendars around this time, each with their own methods of counting and recording years based on lunar or solar observations.
It is important to note that while these civilizations were counting years, their calendars were not standardized like the Gregorian calendar we use today, and different cultures and regions had their own systems for measuring time. The Gregorian calendar, which is the most widely used calendar in the world today, was introduced in 1582 CE by Pope Gregory XIII to improve the accuracy of the Julian calendar.