Types of calendars: ancient, modern and special

A calendar is usually called a certain system, through which it becomes possible to differentiate the flow of time into certain intervals, which helps to streamline the flow of life. Calendars have been huge in the history of mankind, and they were based on different principles. In this article we will discuss the main types of calendars, and also talk about what form our modern time reference system can take.

Origin of the word "calendar"

Before proceeding to a description of the types of number systems themselves, let's find out where the word comes from, which stands for them. The term "calendar" is etymologically derived from the Latin verb caleo, which translates as "proclaim". Another option, which became the source of the word "calendar", is a calendarium. The last in ancient Rome was called the debt book. Caleo preserves for us the memory of the fact that in Rome the beginning of each month in a special way solemnly proclaimed. And as for the debt book, its significance is due to the fact that all interest on debts and loans in Rome was paid on the first day.

Origin of the calendar system

The fact that time flows in a certain circle, humanity has realized long ago on the basis of cyclically recurring events and phenomena, which are quite numerous. This, for example, the change of day and night, the seasons, the rotation of the celestial spheres and so on. Based on them over time, various types of calendars developed. The basic time unit of any of these is the day, which includes one revolution of the Earth around its own axis. Then an important role in history was played by the moon, the phase change of which forms the so-called synodic month. It is referred to as the Greek word "synodos", which translates as "convergence." It is about the convergence in the sky of the sun and the moon. And, finally, the change of four seasons is a tropical year. Its name comes from the Greek "tropos", that is, "turn".

Why do different peoples living on the same planet have different kinds of calendars? The answer lies in the fact that the duration of the daily cycle, the synodic month and the tropical year do not correlate with each other, which provides ample choice in the compilation of the calendar.

Three kinds of calendar

Based on the described values at various times, attempts were made to compile a calendar suitable for the life of society. Some of them were guided only by lunar cycles. Thus, the lunar calendars appeared. As a rule, they counted for twelve months, focused only on the movement of the night light, and did not correlate with the change of seasons. Others, on the contrary, made their calculations only on the basis of a circle of seasons, without regard for the moon and its rhythm. This approach gave rise to solar calendars. Still others took into account both cycles - solar and lunar. And, starting from the latter, they tried, one way or another, to reconcile both with each other. They gave rise to mixed solar-lunar calendars.

Moon calendar

Now we will discuss the nuances of the time calculation system based solely on the motion of the moon. The lunar calendar, as already mentioned, is based on the synodic month - the cycle of changing the lunar phases from the new moon to the full moon. The average duration of such a month is 29.53 days. Therefore, in most lunar calendars, the month lasts 29 or 30 days. In this case, the year most often consists of twelve months. Thus, it turns out that the length of the year is about 354.36 days. As a rule, it is rounded to 354, at the same time introducing periodically a leap year in 355 days. Do it everywhere in many ways. For example, the Turkish cycle is known, where there are three leap years for eight years. Another option, with a ratio of 30/11, is proposed by the Arab system, on the basis of which a traditional Muslim calendar is compiled.

Since the lunar calendars are in no way connected with the movement of the sun, they gradually disagree with it because of the difference in more than ten days a year. So, the cycle of the solar calendar at 34 years corresponds to 35 years of the lunar calendar. Despite this inaccuracy, this system satisfied many people, especially at an early stage of development, when they had a nomadic lifestyle. The moon is easily observable in the sky, and this calendar does not require significant complex calculations. Over time, however, when the role of agriculture increased, its opportunities were insufficient - it required a more rigid binding of the months to the seasons and the range of agricultural work. This stimulated the development of the solar calendar.

Lunar calendar shortcoming

In addition to the fact that the calendar, based entirely on the lunar cycle, differs significantly from the tropical year, it has another significant drawback. It consists in the fact that due to a very complex orbit the duration of the synodic month is continuously changing. The difference can be up to six hours. It should be said that the starting point for the new month in the lunar calendar is not the new moon, which is difficult to observe, and the so-called neomen is the first appearance of a young moon at sunset. This event follows the new moon in 2 or 3 days. At the same time, neo-diversity depends on the time of the year, the duration of the current month and the location of the observer. This means that a calendar calculated in one place will be completely inaccurate for another area. And in general, no system based on the lunar cycles, is able to accurately reflect the real movement of the night luminary.

Solar calendar

The history of the calendar can not be complete without mentioning the solar cycle. I must say that today it is the main form of the calculation of time. It is based on a tropical year, consisting of 365.24 days. To make calculations more precise, leap years are periodically introduced , which collect accumulated "surplus" in one "extra" day. There are various systems of leap-ups, which makes many kinds of calendars based on the movement of the sun known. The date of the reference is traditionally considered the day of the spring equinox. Therefore, one of the requirements of the solar calendar is that each year this event should be on the same date.

The first system of leap-flops was possessed by the Julian calendar. His weak point was that over 128 years he gained one extra day, and the equinox point shifted, respectively, back. This inaccuracy was attempted to correct in various ways. For example, Omar Khayyam proposed a special 33-year cycle, which was then used as the basis for the Persian calendar. Later, on the initiative of Pope Gregory, the Gregorian calendar was introduced, which is the main civil calendar of modern society. He also gradually accumulates one extra day, but this period stretches from 128 years to 3300.

Another attempt to improve the Julian system was made by Milutin Milankovic. He developed the so-called New Calendar calendar, which had already accumulated a mistake in a day at 50,000 years. This is due to a special rule for centuries of the century (they can be considered leap years, only if the division of 900 in the remainder is 2 or 6). The disadvantage of the Gregorian and New Julian calendars, with their accuracy, is the fact that the date of the equinox becomes floating, and falls every year on different days.

The solar-lunar calendar

Finally, touch the solar-lunar calendar. Its essence consists in reconciling in one cycle the movement of the sun with the motion of the moon. To do this, it was necessary to periodically extend the year for one month. It was called embolismic year. In Ancient Greece and Babylon, three additional months were introduced for eight years. Its error is one and a half days for the entire eight-year period. A longer cycle, according to the history of the calendar, was adopted in China, although it was known about it in Babylon and in Greece. Its error is one day for 219 years.

Types of calendars

Now let's talk about what kinds of calendar exist today. It's about constructive, not astronomical features. So, the most popular today are flip-flops, wall-mounted, pocket and tear-off calendars.

Flip Calendars

Another name for this type of typographic publication is the "house". Although some options may have a different design, including a stand of plastic. The latter often form a single whole with a stand for pencils and sections for paper clips. The bottom line is that the calendar is designed so that the months tables are located on different pages, which you need to turn over in a timely manner. Together with the calendar on them is very conveniently located various information or simply beautiful images that are included in the overall design of the room. These products are often used in offices, conveniently located in the corner of the desktop. The flip chart also often serves as a gift or souvenir.

Wall calendar

Many in the kitchen have a calendar attached to the wall, the refrigerator door or the door. Wall calendars are very popular because they are easy to use, and their aesthetic value nowadays makes them an excellent decoration for the home. Sometimes they combine with the technology of "houses". In this case, wall calendars, as a rule, are real albums dedicated to a particular topic. A function, in fact, calculus of time departs in them in the background.

Pocket calendar

This type is probably the most common in our time. Pocket calendars are small cards, on the one hand, there is actually a calendar plate, and on the other - some drawing. Very often such products serve as bookmarks, business cards. Often they are used for advertising purposes. Pocket calendars are kind of postcards that carry an additional function. They can easily be put in a wallet and carried with them, taking out as needed.

Tear-off calendars

The Soviet tear-off calendar is familiar to everyone. Once they met in almost every home, but today their popularity has fallen somewhat, although they are still often met. These products are real books, where each page is allocated for one day of the year. When a new day comes, the previous page comes off. Therefore, it is called detachable. On the back of the page contains some text. As a rule, each such calendar is dedicated to a topic and presents in its framework a rather informative source.

Church calendars

A few words should also be said about what a church calendar is, since many people come to the church or read church literature and come across a system of double dating. In fact, the Orthodox Orthodox calendar refers to the usual Julian calendar. Just two thousand years, he began to lag behind the real astronomical course of time for almost two weeks. The Catholic Church corrected this, resulting in the appearance of the Gregorian calendar. But the Orthodox did not accept this reform. The Russian Orthodox Church and several other independent jurisdictions, for example, still adhere to the Julian calendar. But most of the Orthodox churches in the world still switched to the New Julian calendar, which now coincides with the Gregorian calendar.

The church calendar, therefore, has at least three varieties. In some countries, in addition, churches use their national calendars. For example, the Coptic system of chronology is widespread in Egypt. There are also calendars of other religious organizations. For example, the Vedic, Buddhist, Islamic, Baha'i, and other systems of organizing time are known.

Mayan calendar

In conclusion, let us say a few words about what the ancient Mayan calendar is. In fact, this is not one, but a whole system of different chronology. The civil calendar for the year for Maya Indians was sunny and consisted of 365 days. Its main purpose was to regulate the agricultural life. There was also a ritual calendar, which was called Tzolkin. It is translated as "account of days". It is somewhat unusual in its structure. So, the calendar for the year for Tzolkin contained not 365, but 260 days. The latter were divided into two cycles - twenty days and thirteen days. The days of the first of them had their own name, and the second contained only the serial number. The Mayan system of time counting included such periods as tuna (360 days), katuny (20 tones), baktuns (20 katuns). The greatest was the era of 260 katuns. In terms of the system of accounts we are accustomed to, this is 5125 years. On December 21, 2012, one such epoch, called the fifth sun, ended, and a new era of the sixth began.