The ancient peoples of Mesopotamia (the region between the Tigris and Euphrates rivers) achieved a high level of culture and scientific knowledge (especially in the field of mathematics and astronomy), the peak of which was the Babylonian calendar. Using primitive devices for observing the starry sky, the Babylonians created such a well-developed system of timekeeping that it was borrowed by other nations, including ancient Jews.
Kingdom of Babylon
Politically, this area was not unified. Several large cities (Uruk, Sippar, Babylon) were in a constant struggle for the role of the center of the nearby territory. In its history, Babylonia went through several stages of both relative consolidation around one of the strengthened cities, and fragmentation and significant weakening. The history of this territory as an independent state entity covers the period from the second millennium to 539 BC. e. when Babylon was captured by the Persians.
Culture and Science of Babylon
Scientific knowledge and cultural achievements of ancient Babylonia, as well as other ancient Eastern societies, were aimed at practical application. This applies both to ziggurats - multistage pyramids where religious rites and astronomical observations were carried out - and cuneiform writing, the appearance of which was caused by the need to fix the increased volume of knowledge about the world. The Babylonian calendar owed its appearance to the need for timely agricultural work. Moreover, its occurrence would be impossible without developed mathematical concepts. It should also be borne in mind that the Babylonian priests relied heavily on the knowledge of the ancient Sumerians.
The modern division of hours by 60 minutes and minutes by 60 seconds stems from the Babylonian six-decimal system. From there, there is the allocation of twelve months a year, a seven-day week and 24 hours a day. Highlighting the components of a time period would be impossible without the ability to work with fractions.
The astronomical knowledge of Babylonia reached such a high level that the priests - it was in the ranks of the clergy that scientific knowledge was accumulating - could predict solar and lunar eclipses. The astronomical tables compiled by them have reached our days, the error in which, taking into account the devices then available, seems insignificant.
Babylonian calendar structure
Historically, the first visible embodiment of the cyclicity of time was the change of phases of the moon. That is why the oldest calendars - including the Babylonian ones - were lunar. A full cycle of phase changes occurs on average in 29-30 days, which determines the duration of the lunar month. Over time, an error accumulates, so additional days were used to synchronize the calendar and natural phenomena.
Moreover, the lunar year of 354 days with time less and less coincided with the change of seasons and spill dates. This is due to the fact that the tropical year, based on the rotation of the Earth around the Sun, was much longer. There was a need to create a lunar-solar calendar. When the discrepancy between the timing and reality turned out to be too large, the Babylonian ruler initiated amendments to the calendar. Most often, they consisted in the introduction of an additional month.
Resolving Calendar Errors
Such changes were based on practical astronomical observations and mathematical knowledge. Calculations of the priests showed that the Earth makes a complete revolution around the Sun in approximately 365 days. Next, the smallest total multiple between the number of lunar and sunny days in a month was calculated with the assumption that the year consists of 12 months. It turned out that the same number of days in two time systems accumulates over 8 years. Further calculations show that to eliminate the difference every 8 years, you need to add three additional months.
This method did not eliminate the error completely. Every eight years, a difference of one or two days accumulated between the lunar-solar calendar and reality. But this discrepancy was almost imperceptible, since a full month accumulated in about 150 years. Later, in order to increase the accuracy of the calendar, instead of an eight-year cycle, a nineteen-year cycle began, where the error instead of a couple of days was two hours.
Division of the year into months
The calendar of Ancient Babylonia was based on the reckoning of the city of Ur. It was officially distributed throughout the Mesopotamia under the rule of King Hammurabi.
The names of the months of the Babylonian calendar in Akkadian are as follows:
- Nisanu (March-April).
- Airu (April-May).
- Sivanu (May-June).
- Duuzu (June-July).
- Abu (July-August).
- Ululu (August-September).
- Tashritu (September-October).
- Arakhsamnu (October-November).
- Kislivu (November-December).
- Thabitu (December-January).
- Shabathu (January-February).
- Adaru (February-March).
The beginning of the new year coincided with the date of the vernal equinox - March 22. Each odd month was divided into 30 days, and each even month was divided by 29. The additional month bore the same name as the previous one. In the period of the eight-year cycle, it was ululu, in the period of the nineteen-year cycle, in the Adara.
Babylonian Chronology
A feature of the Babylonian calendar was the allocation of intervals larger than a year according to the dates of the reign of the kings. The era, according to which a count of years was kept, was associated with the accession of Nabonassar, which happened on February 27, 747 BC. e. In fact, this is the first system of chronology based on a real and accurately dated historical event. Subsequently, Claudius Ptolemy, one of the most famous ancient astronomers, actively used the Nabonassar era.
A disadvantage of such a system is its defenselessness from political changes. After the loss of independence by Babylonia, the era of Nabonassar was rejected. It was replaced by the reckoning from the date of the accession of Seleucus - October 1, 312 BC. e.
Calendar value
The accuracy and sophistication of the Babylonian calculus served him well. Its virtues were appreciated by the peoples who somehow interacted with this ancient country. The Assyrians were one of the first Babylonian lunar-solar calendars. It happened at the turn of the XIII-XII centuries BC. e. The ancient Jews also gave a detailed description of the Babylonian calendar, and the names of the months, aligned with the spelling and pronunciation of the Aramaic language, were preserved.
The division of time intervals into component parts adopted in Babylonia turned out to be even more stable. It is based on the modern allocation of hours and minutes. Thus, modern people use the knowledge first obtained over four thousand years ago.