|
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Julian Calendar
The Julian calendar is a solar calendar of 365 days in every year with an additional leap day every fourth year (without exception). The Julian calendar is still used as a religious calendar in parts of the Eastern Orthodox Church and in parts of Oriental Orthodox Churches, Oriental Orthodoxy as well as by the Amazigh, Amazigh people (also known as the Berbers). The Julian calendar was proposed in 46 BC by (and takes its name from) Julius Caesar, as a reform of the earlier Roman calendar, which was largely a lunisolar calendar, lunisolar one. It took effect on , by his edict. Caesar's 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 revised calendar. Ancient Romans typically designated years by the names of ruling consuls; the ''Anno Domini'' system of numbering years was not devised until 525, and became widespread in Europe in the eighth cent ... [...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 (which is the year of the epoch of the era). 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, a data interchange standard for certain time and calendar information (where year zero coincides with the Gregorian year ; . There is also a year zero in most Buddhist and Hindu calendars. History 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 of Christians. In the prefa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Julian Date
The Julian day is a continuous count of days from the beginning of the Julian period; it 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, derived from three multi-year cycles: the Indiction, Solar, and Lunar cycles. The last year that was simultaneously the beginning of all three cycles was , so that is year 1 of the current Julian period, making AD year of that Period. The next Julian Period begins in the year AD 3268. 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) has the same epoch as the Julian period, but counts the number of days since the epoch rather than the number of years since then. Specifically, ... [...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 days or 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 an extra day ("leap day" or "intercalary day") to a common year of 365 days, about once every four years, creating a leap year that has 366 days ( Julian, Gregorian and Indian national calendars). The Decree of Canopus, issued by the pharaoh Ptolemy III Euergetes of Ancient Egypt in 239 BC, decreed a solar leap day system; an Egyptian leap year was not adopted until 25 BC, when the Roman Emperor Augustus instituted a reformed Alexandrian cal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roman Calendar
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 Julius Caesar in 46 BC. According to most Roman accounts, #Romulus, their original calendar was established by their Roman legend, legendary list of kings of Rome, first king Romulus. It consisted of ten months, beginning in spring with March and leaving winter as an unassigned span of days before the next year. These months each had 30 or 31 days and ran for 38 nundinal cycles, each forming a kind of eight-day weeknine days inclusive counting, counted inclusively in the Roman mannerand ending with religious rituals and a Roman commerce, public market. This fixed calendar bore traces of its origin as an observational calendar, observational lunar calendar, lunar one. In particular, the most important days of each monthits kalends, nones (calendar), nones, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Julian Calendar
The Julian calendar is a solar calendar of 365 days in every year with an additional leap day every fourth year (without exception). The Julian calendar is still used as a religious calendar in parts of the Eastern Orthodox Church and in parts of Oriental Orthodox Churches, Oriental Orthodoxy as well as by the Amazigh, Amazigh people (also known as the Berbers). The Julian calendar was proposed in 46 BC by (and takes its name from) Julius Caesar, as a reform of the earlier Roman calendar, which was largely a lunisolar calendar, lunisolar one. It took effect on , by his edict. Caesar's 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 revised calendar. Ancient Romans typically designated years by the names of ruling consuls; the ''Anno Domini'' system of numbering years was not devised until 525, and became widespread in Europe in the eighth cent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Roman Empire
The Roman Empire ruled the Mediterranean and much of Europe, Western Asia and North Africa. The Roman people, Romans conquered most of this during the Roman Republic, Republic, and it was ruled by emperors following Octavian's assumption of effective sole rule in 27 BC. The Western Roman Empire, western empire collapsed in 476 AD, but the Byzantine Empire, eastern empire lasted until the fall of Constantinople in 1453. By 100 BC, the city of Rome had expanded its rule from the Italian peninsula to most of the Mediterranean Sea, Mediterranean and beyond. However, it was severely destabilised by List of Roman civil wars and revolts, civil wars and political conflicts, which culminated in the Wars of Augustus, victory of Octavian over Mark Antony and Cleopatra at the Battle of Actium in 31 BC, and the subsequent conquest of the Ptolemaic Kingdom in Egypt. In 27 BC, the Roman Senate granted Octavian overarching military power () and the new title of ''Augustus (title), Augustus'' ... [...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 (which is the year of the epoch of the era). 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, a data interchange standard for certain time and calendar information (where year zero coincides with the Gregorian year ; . There is also a year zero in most Buddhist and Hindu calendars. History 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 of Christians. In the prefa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Timeline
A timeline is a list of events displayed 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. More usually, "timeline" refers merely to a data set which could be displayed as described above. For example, this meaning is used ... [...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. He was known as Cassini II. Biography Cassini was born at the Paris Observatory. He was first admitted to Collège Mazarin after brief studies at his home observatory under his father. Later, he was 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. While in England, he was acquainted with other famous astronomers such as Newton and Halley. 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 Pa ... [...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 nu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
