When and who establishes the current calendar of months?

The first human beings who began to calculate time, did so by observing the periods of light and dark that alternated continuously. The solar day is considered the earliest form of the calendar. The second basic type of calendar was the arbitrary calendar, which was created by counting the number of days over and over again, either towards infinity or in a cycle. However, there were several problems with the arbitrary timing.

In the first place, the farmers of the first civilizations could not calculate the perfect time to plant their crops. Planting crops is an activity that is closely related to the seasons, and the arbitrary timing was not based on the length of the seasons. Therefore, humans began to observe the passage of the sun through a fixed point, and this practice was the forerunner of the solar calendar. Calendars that were based on lunar and stellar cycles were also used in ancient times.

Previous historical calendars

One of the first truly scientific calendars was the egyptian calendar. In it, a year was made up of 12 months, and each month had 30 days. The months were divided into three weeks, and each week lasted 10 days. Later, the Babylonian calendar, and it was a lunisolar calendar. The years in this calendar were made up of 12 lunar months, and each month would begin when a new crescent moon appeared.

Harvest moon

The Greeks used a calendar very similar to the Babylonian calendar, but they also had other calendars, such as the democratic state calendar with 10 arbitrary months and an agricultural calendar. The first Roman calendar was created by Romulus, and it had 10 months in a year, and each month lasted 30 or 31 days. The Romans had several calendars, the most notable of which was the Julian calendar.

The Julian calendar

The Julian calendar was introduced in 45 BC. C. by Julius Caesar. Although it was 12 months old, many of its months were shorter than those of the modern calendar. As such, a Julian year only consisted of 355 days. Before Julius Caesar’s reforms, the year began on March 31. A leap month was also created with 23 or 24 days to keep the calendar correctly aligned with the cycle of the seasons.

The Roman calendar also had a recurring cycle of weeks, which is similar to the modern cycle, but each week consisted of eight days. Julius Caesar introduced a series of reforms to the ancient Roman calendar. One of them was adding days to February to make it a 28-day month. Caesar introduced the leap year rule, which stated that all leap years can be divided equally by four.

The Gregorian conversion

In the year 1582, Pope Gregory XIII decreed that there should be a change in the Julian calendar. The Gregorian calendar was a theoretical calendar, and it was created from very precise calculations of the vernal equinoxes.. The Julian calendar was based on the assumption that the duration between vernal equinoxes is 365 and a quarter days, but it is actually about 11 minutes less.

Calendar and notepad

As such, the Gregorian calendar had three leap days removed every 400 years. In addition, changes were made to the lunar cycle, which helped in the calculation of Passover. Many European countries did not adopt the Gregorian calendar when it was introduced, mainly due to the Protestant Reformation that was taking place at the time. However, by the 20th century, the calendar became the standard calendar in Europe. Today is the most used calendar in the world.