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The traditional Chinese calendar is a lunisolar calendar which identifies years, months, and days according to astronomical phenomena. In China, it is defined by the Chinese national standard GB/T 33661–2017, "Calculation and Promulgation of the Chinese Calendar", issued by the Standardization Administration of China on May 12, 2017. Traditional Chinese calendar also known as these five titles: Nongli Calendar, Jiuli Calendar, Laoli Calendar, Zhongli Calendar, Huali Calendar
The French Republican calendar, also commonly called the French Revolutionary calendar, was a calendar created and implemented during the French Revolution, and used by the French government for about 12 years from late 1793 to 1805, and for 18 days by the Paris Commune in 1871, and meant to replace the Gregorian calendar.
An hour is a unit of time historically reckoned as 1⁄24 of a day and defined contemporarily as exactly 3,600 seconds (SI). There are 60 minutes in an hour, and 24 hours in a day.
Intercalation or embolism in timekeeping is the insertion of a leap day, week, or month into some calendar years to make the calendar follow the seasons or moon phases. Lunisolar calendars may require intercalations of both days and months.
The Julian calendar is a solar calendar of 365 days in every year with an additional leap day every fourth year. The Julian calendar is still used in parts of the Eastern Orthodox Church and in parts of Oriental Orthodoxy as well as by the Berbers, whereas the Gregorian calendar is used in most parts of the world.
A leap year is a calendar year that contains an additional day added to keep the calendar year synchronized with the astronomical year or seasonal year. Because astronomical events and seasons do not repeat in a whole number of days, calendars that have a constant number of days in each year will unavoidably drift over time with respect to the event that the year is supposed to track, such as seasons. By inserting ("intercalating") an additional day or month into some years, the drift between a civilization's dating system and the physical properties of the Solar System can be corrected. A year that is not a leap year is a common year.
A month is a unit of time, used with calendars, that is approximately as long as a natural orbital period of the Moon; the words month and Moon are cognates. The traditional concept arose with the cycle of Moon phases; such lunar months ("lunations") are synodic months and last approximately 29.53 days. From excavated tally sticks, researchers have deduced that people counted days in relation to the Moon's phases as early as the Paleolithic age. Synodic months, based on the Moon's orbital period with respect to the Earth–Sun line, are still the basis of many calendars today, and are used to divide the year.
The Roman calendar was the calendar used by the Roman Kingdom and Roman Republic. Although the term is primarily used for Rome's pre-Julian calendars, it is often used inclusively of the Julian calendar established by the reforms of the dictator Julius Caesar and emperor Augustus in the late 1st century BC.
A solar calendar is a calendar whose dates indicate the season or almost equivalently the apparent position of the Sun relative to the stars. The Gregorian calendar, widely accepted as a standard in the world, is an example of a solar calendar. The main other types of calendar are lunar calendar and lunisolar calendar, whose months correspond to cycles of Moon phases. The months of the Gregorian calendar do not correspond to cycles of the Moon phase.
The Season of the Inundation or Flood was the first season of the lunar and civil Egyptian calendars. It fell after the intercalary month of Days over the Year and before the Season of the Emergence. In the Coptic and Egyptian calendars this season begins at the start of the month of Thout, continues through the months of Paopi and Hathor, before concluding at the end of Koiak.
The Season of the Emergence was the second season of the lunar and civil Egyptian calendars. It fell after the Season of the Inundation and before the Season of the Harvest. In the Coptic and Egyptian calendars this season begins at the start of the month of Tobi, continues through the months of Meshir and Paremhat, before concluding at the end of Parmouti.
The Season of the Harvest or Low Water was the third and final season of the lunar and civil Egyptian calendars. It fell after the Season of the Emergence and before the spiritually dangerous intercalary month, after which the New Year's festivities began the Season of the Inundation (Ꜣḫt). In the Coptic and Egyptian calendars this season begins at the start of the month of Pashons, continues through the months of Paoni and Epip, before concluding at the end of Mesori.
The ancient Egyptian calendar – a civil calendar – was a solar calendar with a 365-day year. The year consisted of three seasons of 120 days each, plus an intercalary month of five epagomenal days treated as outside of the year proper. Each season was divided into four months of 30 days. These twelve months were initially numbered within each season but came to also be known by the names of their principal festivals. Each month was divided into three 10-day periods known as decans or decades. It has been suggested that during the Nineteenth Dynasty and the Twentieth Dynasty the last two days of each decan were usually treated as a kind of weekend for the royal craftsmen, with royal artisans free from work.
The history of calendars covers practices with ancient roots as people created and used various methods to keep track of days and larger divisions of time. Calendars commonly serve both cultural and practical purposes and are often connected to astronomy and agriculture.
Calendar reform or calendrical reform is any significant revision of a calendar system. The term sometimes is used instead for a proposal to switch to a different calendar design.
The Attic calendar or Athenian calendar is the lunisolar calendar beginning in midsummer with the lunar month of Hekatombaion, in use in ancient Attica, the ancestral territory of the Athenian polis. It is sometimes called the Greek calendar because of Athens's cultural importance, but it is only one of many ancient Greek calendars.
Various ancient Greek calendars began in most states of ancient Greece between Autumn and Winter except for the Attic calendar, which began in Summer.
The intercalary month or epagomenal days of the ancient Egyptian, Coptic, and Ethiopian calendars are a period of five days in common years and six days in leap years in addition to those calendars' 12 standard months, sometimes reckoned as their thirteenth month. They originated as a periodic measure to ensure that the heliacal rising of Sirius would occur in the 12th month of the Egyptian lunar calendar but became a regular feature of the civil calendar and its descendants. Coptic and Ethiopian leap days occur in the year preceding Julian and Gregorian leap years.
Decimal time is the representation of the time of day using units which are decimally related. This term is often used specifically to refer to the time system used in France from 1794 to 1800, during the French Revolution, which divided the day into 10 decimal hours, each decimal hour into 100 decimal minutes and each decimal minute into 100 decimal seconds, as opposed to the more familiar standard time, which divides the day into 24 hours, each hour into 60 minutes and each minute into 60 seconds.
A unit of time is any particular time interval, used as a standard way of measuring or expressing duration. The base unit of time in the International System of Units (SI), and by extension most of the Western world, is the second, defined as about 9 billion oscillations of the caesium atom. The exact modern SI definition is "[The second] is defined by taking the fixed numerical value of the cesium frequency, ΔνCs, the unperturbed ground-state hyperfine transition frequency of the cesium 133 atom, to be 9 192 631 770 when expressed in the unit Hz, which is equal to s−1."
References
- ↑ "Ancient Egyptian Calendar and Chronology" (PDF). Rutgers University. Archived from the original (PDF) on 19 July 2010. Retrieved 10 June 2012.
- 1 2 Konstantin, Bikos; Hocken, Vigdis. "The Roman calendar". Stavanger, Norway: Time and Date AS. Retrieved 10 June 2012.
- 1 2 3 Sanja Perovic (2012). "French Republican Calendar: Time, History and the Revolutionary Event". Journal for Eighteenth-Century Studies. 35: 1–16. doi:10.1111/j.1754-0208.2011.00408.x.
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