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Proleptic Julian Calendar
The proleptic Julian calendar is produced by extending the Julian calendar backwards to dates preceding AD 8 when the quadrennial leap year stabilized. The leap years that were actually observed between the implementation of the Julian calendar in 45 BC and AD 8 were erratic (see the Julian calendar article for details). A calendar obtained by extension earlier in time than its invention or implementation is called the " proleptic" version of the calendar. Likewise, the proleptic Gregorian calendar is occasionally used to specify dates before the introduction of the Gregorian calendar in 1582. Because the Julian calendar was used before that time, one must explicitly state that a given quoted date is based on the proleptic Gregorian calendar if that is the case. The Julian calendar itself was introduced by Julius Caesar, and as such is older than the introduction of the Anno Domini era (or the "Common Era"), counting years since the birth of Christ as calculated by Dionysus Ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Julian Calendar
The Julian calendar, proposed by Roman consul Julius Caesar in 46 BC, was a reform of the Roman calendar. It took effect on , by edict. It was designed with the aid of Greek mathematicians and astronomers such as Sosigenes of Alexandria. The calendar became the predominant calendar in the Roman Empire and subsequently most of the Western world for more than 1,600 years until 1582, when Pope Gregory XIII promulgated a minor modification to reduce the average length of the year from 365.25 days to 365.2425 days and thus corrected the Julian calendar's drift against the Tropical year, solar year. adoption of the Gregorian calendar, Worldwide adoption of this revised calendar, which became known as the Gregorian calendar, took place over the subsequent centuries, first in Catholic Church, Catholic countries and subsequently in Protestantism, Protestant countries of the Western Christianity, Western Christian world. The Julian calendar is still used in parts of the East ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Year Zero
A year zero does not exist in the Anno Domini (AD) calendar year system commonly used to number years in the Gregorian calendar (nor in its predecessor, the Julian calendar); in this system, the year is followed directly by year . However, there is a year zero in both the astronomical year numbering system (where it coincides with the Julian year ), and the ISO 8601:2004 system, the interchange standard for all calendar numbering systems (where year zero coincides with the Gregorian year ; see conversion table). There is also a year zero in most Buddhist and Hindu calendars. Historical, astronomical and ISO year numbering systems Historians The ''Anno Domini'' era was introduced in 525 by Scythian monk Dionysius Exiguus (c. 470 – c. 544), who used it to identify the years on his Easter table. He introduced the new era to avoid using the '' Diocletian era'', based on the accession of Roman Emperor Diocletian, as he did not wish to continue the memory of a persecutor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Julian Date
The Julian day is the continuous count of days since the beginning of the Julian period, and is used primarily by astronomers, and in software for easily calculating elapsed days between two events (e.g. food production date and sell by date). The Julian period is a chronological interval of 7980 years; year 1 of the Julian Period was . The Julian calendar year is year of the current Julian Period. The next Julian Period begins in the year . Historians used the period to identify Julian calendar years within which an event occurred when no such year was given in the historical record, or when the year given by previous historians was incorrect. The Julian day number (JDN) is the integer assigned to a whole solar day in the Julian day count starting from noon Universal Time, with Julian day number 0 assigned to the day starting at noon on Monday, January 1, 4713 BC, proleptic Julian calendar (November 24, 4714 BC, in the proleptic Gregorian calendar), a date at whi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intercalation (timekeeping)
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. Solar calendars The solar or tropical year does not have a whole number of days (it is about 365.24 days), but a calendar year must have a whole number of days. The most common way to reconcile the two is to vary the number of days in the calendar year. In solar calendars, this is done by adding to a common year of 365 days, an extra day ("leap day" or "intercalary day") about every four years, causing a leap year to have 366 days ( Julian, Gregorian and Indian national calendars). The Decree of Canopus, which was issued by the pharaoh Ptolemy III Euergetes of Ancient Egypt in 239 BCE, decreed a solar leap day system; an Egyptian leap year was not adopted until 25 BC, when the Roman Emperor Augustus successfully instituted a re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roman Calendar
The Roman calendar was the calendar used by the Roman Kingdom and Roman Republic. The term often includes the Julian calendar established by the reforms of the dictator Julius Caesar and emperor Augustus in the late 1stcenturyBC and sometimes includes any system dated by inclusive counting towards months' kalends, nones, and ides in the Roman manner. The term usually excludes the Alexandrian calendar of Roman Egypt, which continued the unique months of that land's former calendar; the Byzantine calendar of the later Roman Empire, which usually dated the Roman months in the simple count of the ancient Greek calendars; and the Gregorian calendar, which refined the Julian system to bring it into still closer alignment with the tropical year. Roman dates were counted inclusively forward to the next of three principal days: the first of the month (the kalends), a day shortly before the middle of the month (the ides), and eight days—nine, counting inclusively—before thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Julian Calendar
The Julian calendar, proposed by Roman consul Julius Caesar in 46 BC, was a reform of the Roman calendar. It took effect on , by edict. It was designed with the aid of Greek mathematicians and astronomers such as Sosigenes of Alexandria. The calendar became the predominant calendar in the Roman Empire and subsequently most of the Western world for more than 1,600 years until 1582, when Pope Gregory XIII promulgated a minor modification to reduce the average length of the year from 365.25 days to 365.2425 days and thus corrected the Julian calendar's drift against the Tropical year, solar year. adoption of the Gregorian calendar, Worldwide adoption of this revised calendar, which became known as the Gregorian calendar, took place over the subsequent centuries, first in Catholic Church, Catholic countries and subsequently in Protestantism, Protestant countries of the Western Christianity, Western Christian world. The Julian calendar is still used in parts of the East ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roman Empire
The Roman Empire ( la, Imperium Romanum ; grc-gre, Βασιλεία τῶν Ῥωμαίων, Basileía tôn Rhōmaíōn) was the post- Republican period of ancient Rome. As a polity, it included large territorial holdings around the Mediterranean Sea in Europe, North Africa, and Western Asia, and was ruled by emperors. From the accession of Caesar Augustus as the first Roman emperor to the military anarchy of the 3rd century, it was a Principate with Italia as the metropole of its provinces and the city of Rome as its sole capital. The Empire was later ruled by multiple emperors who shared control over the Western Roman Empire and the Eastern Roman Empire. The city of Rome remained the nominal capital of both parts until AD 476 when the imperial insignia were sent to Constantinople following the capture of the Western capital of Ravenna by the Germanic barbarians. The adoption of Christianity as the state church of the Roman Empire in AD 380 and the fall of the Western ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Year 0
A year zero does not exist in the Anno Domini (AD) calendar year system commonly used to number years in the Gregorian calendar (nor in its predecessor, the Julian calendar); in this system, the year is followed directly by year . However, there is a year zero in both the astronomical year numbering system (where it coincides with the Julian year ), and the ISO 8601:2004 system, the interchange standard for all calendar numbering systems (where year zero coincides with the Gregorian year ; see conversion table). There is also a year zero in most Buddhist and Hindu calendars. Historical, astronomical and ISO year numbering systems Historians The ''Anno Domini'' era was introduced in 525 by Scythian monk Dionysius Exiguus (c. 470 – c. 544), who used it to identify the years on his Easter table. He introduced the new era to avoid using the '' Diocletian era'', based on the accession of Roman Emperor Diocletian, as he did not wish to continue the memory of a persecutor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Timeline
A timeline is a display of a list of events in chronological order. It is typically a graphic design showing a long bar labelled with dates paralleling it, and usually contemporaneous events. Timelines can use any suitable scale representing time, suiting the subject and data; many use a linear scale, in which a unit of distance is equal to a set amount of time. This timescale is dependent on the events in the timeline. A timeline of evolution can be over millions of years, whereas a timeline for the day of the September 11 attacks can take place over minutes, and that of an explosion over milliseconds. While many timelines use a linear timescale—especially where very large or small timespans are relevant -- logarithmic timelines entail a logarithmic scale of time; some "hurry up and wait" chronologies are depicted with zoom lens metaphors. History Time and space, particularly the line, are intertwined concepts in human thought. The line is ubiquitous in clocks ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Year
New Year is the time or day currently at which a new calendar year begins and the calendar's year count increments by one. Many cultures celebrate the event in some manner. In the Gregorian calendar, the most widely used calendar system today, New Year occurs on January 1 ( New Year's Day, preceded by New Year's Eve). This was also the first day of the year in the original Julian calendar and the Roman calendar (after 153 BC). Other cultures observe their traditional or religious New Year's Day according to their own customs, typically (though not invariably) because they use a lunar calendar or a lunisolar calendar. Chinese New Year, the Islamic New Year, Tamil New Year (Puthandu), and the Jewish New Year are among well-known examples. India, Nepal, and other countries also celebrate New Year on dates according to their own calendars that are movable in the Gregorian calendar. During the Middle Ages in Western Europe, while the Julian calendar was still in use, au ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jacques Cassini
Jacques Cassini (18 February 1677 – 16 April 1756) was a French astronomer, son of the famous Italian astronomer Giovanni Domenico Cassini. Cassini was born at the Paris Observatory. Admitted at the age of seventeen to membership of the French Academy of Sciences, he was elected in 1696 a fellow of the Royal Society of London, and became ''maître des comptes'' in 1706. Having succeeded to his father's position at the observatory in 1712, in 1713 he extended the Paris meridian, measuring the arc of the meridian from Dunkirk to Perpignan, and published the results in a volume entitled ''Traité de la grandeur et de la figure de la terre'' (1720). His two separate calculations for a degree of meridian arc were 57,097 ''toises de Paris'' (111.282 km) and 57,061 toises (111.211 km), giving results for Earth's radius of 3,271,420 toises (6,375.998 km) and 3,269,297 toises (6,371.860 km), respectively. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomical Year Numbering
Astronomical year numbering is based on AD/ CE year numbering, but follows normal decimal integer numbering more strictly. Thus, it has a year 0; the years before that are designated with negative numbers and the years after that are designated with positive numbers. Astronomers use the Julian calendar for years before 1582, including the year 0, and the Gregorian calendar for years after 1582, as exemplified by Jacques Cassini (1740),Jacques Cassini, Tables Astronomiques' (1740), Explication et Usage pp. 5 (PA5), 7 (PA7), Tables pp. 10 (RA1-PA10), 22 (RA1-PA22), 63 (RA1-PA63), 77 (RA1-PA77), 91 (RA1-PA91), 105 (RA1-PA105), 119 (RA1-PA119). Simon Newcomb (1898) and Fred Espenak (2007).Fred EspenakPhases of the Moon: −99 to 0 (100 to 1 BCE) ''NASA Eclipse web site'' The prefix AD and the suffixes CE, BC or BCE (Common Era, Before Christ or Before Common Era) are dropped. The year 1 BC/BCE is numbered 0, the year 2 BC is numbered −1, and in general the year ''n'' BC/BCE is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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