As we approaching the end of 2021, only a few days left to reach the year 2022. But when did this time system begin ? Who invented the calendar system ? We will learn that from this article.

Most ancient societies used nature units to count the time such as the day, the Solar (Sun) and the lunation (Moon). The Sumerian calendar in Mesopotamia was the earliest system, it divided a year into 12 lunar months each consisting of 29 or 30 days. Followed by the Egyptian, Assyrian and Elamite calendars which all date to the Bronze Age in 3100 BC.

The Egyptians invented a year with 365 days divided into three seasons, each of them consisted of four months of 30 days each. So that the 12 months in one year were equal to 360 days plus five extra days as intercalary days.

According to Wikipedia, the term calendars itself is taken from the calends or kalends, the first day of every month in the Roman Calendar. The English word calendar is derived from the Latin calendarium meaning “interest register” or “account book”.

The Roman year initially had ten months which refer to the legendary first king Romulus. He named the first month of a year as Martius, after his own father, Mars, the god of war.

During the Iron Age record a larger number of calendar systems appeared based on the Assyrian and Babylonian calendars. Including the Persian Empire calendar and the Zoroastrian calendar. The oldest calendar in history that still in use is the Jewish calendar. It’s been used since the 9th century BC. This system based on biblical calculations of the creation at 3761 BC.

People’s Republic of China uses the Gregorian calendar for daily purposes but they use a special Chinese calendar for determining festivals. The start of this Chinese calendar can be traced back to the 14th Century BC.