A calendar is a system for calculating sufficiently large time intervals, which is based on the periodicity of the movement of celestial bodies. Solar calendars are based on the movement of the Sun, lunar calendars are based on the movement of the Moon, lunisolar calendars are based on the movement of the Moon and the Sun at the same time.
One of the important units of any calendar is the week. A week is a period of time of seven days. For a person who effectively plans his work activities, a week, as a unit of time, is of great importance.
Calendar history
The term calendar itself came to us from Ancient Rome and translated from the Latin calendarium - debt book. History says that it was customary for the Romans to repay debts and pay interest on them on the first days of the month, on the days of the so-called calends.
However, the first analogues of calendars appeared long before the foundation of the Roman Empire.
In the vicinity of the town of Nabta Playa, which is located about 800 kilometers from Cairo, perhaps the first annual calendar circle in the history of mankind was discovered. It was created by the semi-nomadic tribes of pastoralists who inhabited the territory of modern Egypt in those days. With the help of this circle, the starting point of which was the appearance of the star Sirius in the sky, the inhabitants of the tribe tracked the beginning of the rainy season. Heavy rainfall turned the hot desert into a real oasis with meadows ideal for grazing.
At about the same period of history, an analogue of the calendar appeared among the tribes that inhabited the lands of present-day Germany. In history, it has been preserved as the Gosek circle, the starting point of which was the day of the winter solstice.
The following references to the mechanisms of time calculation refer to Ancient Egypt. Here, the calendar year was the time interval between two adjacent heliacal risings of the star Sirius. The Egyptians needed a calendar to determine the moments of the floods of the Nile River, repeating from year to year. A natural phenomenon could destroy all the crops of the inhabitants of Ancient Egypt. But, knowing in advance when this would happen, the farmers harvested their crops in advance and prepared for the cultivation of the soil, which after the end of the floods became more fertile and pliable for cultivation.
It is noteworthy that the ancient calendars did not have a clear organization, and in different cultures they had an original structure. So, for example, the Celts divided the week into 9 days, among the Egyptians it consisted of 10, and the ancient Germans lived for long weeks, consisting of as many as 14 days.
Weeks consisting of 7 days first appeared in the Ancient East. Each day of the week was given the name of a celestial body: Monday - the Moon, Tuesday - Mars, Wednesday - Mercury, Thursday - Jupiter, Friday - Venus, Saturday - Saturn, Sunday - the Sun.
The seven-day week also corresponds to the biblical scriptures, according to which God was engaged in the creation of the world for six whole days, and on the seventh day he finally decided to rest.
The final concept of the seven-day week was established by the Romans. It all started with the fact that the astronomer Sosigenes of Alexandria, on the orders of Caesar, developed the so-called Julian calendar, which had 12 months and 365 days. Further, the Romans spread this calendar throughout the empire, from hot Egypt to the endless forests of Germany.
The Julian calendar lasted until the 15th century, after which Pope Gregory XIII replaced it with the Gregorian. It practically did not differ from its predecessor, but was more accurate and closer to the correct time for the change of seasons. Today, most countries in the world use the Gregorian calendar.
The need for the introduction of calendars and their analogues among the peoples of antiquity and the gradual movement of all civilizations towards a single organized calendar testify to the special relationship of people to time. A calendar is not only a great tool for organizing, but also an indispensable tool for recording important dates and events in history, allowing you to pass reliable information to future generations of people.
