Antoninus Pius

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Antoninus Pius

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Antoninus Pius

Julian calendar


The ordinary year in the previous Roman calendar consisted of 12 months, for a total of 355 days. In addition, a 27-day intercalary month, the Mensis Intercalaris, was sometimes inserted between February and March. This intercalary month was formed by inserting 22 days after the first 23 or 24 days of February; the last five days of February, which counted down toward the start of March, become the last five days of Intercalaris. The net effect was to add 22 or 23 days to the year, forming an intercalary year of 377 or 378 days.

According to the later writers Censorinus and Macrobius, the ideal intercalary cycle consisted of ordinary years of 355 days alternating with intercalary years, alternately 377 and 378 days long. On this system, the average Roman year would have had 366 days over four years, giving it an average drift of one day per year relative to any solstice or equinox. Macrobius describes a further refinement wherein, for 8 years out of 24, there were only three intercalary years, each of 377 days. This refinement averages the length of the year to 365 days over 24 years. In practice, intercalations did not occur schematically according to these ideal systems, but were determined by the pontifices. So far as can be determined from the historical evidence, they were much less regular than these ideal schemes suggest. They usually occurred every second or third year, but were sometimes omitted for much longer, and occasionally occurred in two consecutive years.

If managed correctly this system allowed the Roman year, on average, to stay roughly aligned to a tropical year. However, since the Pontifices were often politicians, and because a Roman magistrate's term of office corresponded with a calendar year, this power was prone to abuse: a Pontifex could lengthen a year in which he or one of his political allies was in office, or refuse to lengthen one in which his opponents were in power. If too many intercalations were omitted, as happened after the Second Punic War and during the Civil Wars, the calendar would drift rapidly out of alignment with the tropical year. Moreover, because intercalations were often determined quite late, the average Roman citizen often did not know the date, particularly if he were some distance from the city. For these reasons, the last years of the pre-Julian calendar were later known as "years of confusion". The problems became particularly acute during the years of Julius Caesar's pontificate before the reform, 6346 BC, when there were only five intercalary months, whereas there should have been eight, and none at all during the five Roman years before 46 BC. For example, Caesar crossed the Rubicon on January 10, 49 BC of the official calendar, but the official calendar had drifted so far away from the seasons that it was actually mid-autumn.

The reform was intended to correct this problem permanently, by creating a calendar that remained aligned to the sun without any human intervention.

Julian reform

The first step of the reform was to realign the start of the calendar year (1 January) to the tropical year by making 46 BC 445 days long, compensating for the intercalations which had been missed during Caesar's pontificate. This year had already been extended from 355 to 378 days by the insertion of a regular intercalary month in February. When Caesar decreed the reform, probably shortly after his return from the African campaign in late Quintilis (July), he added 67 (= 22 + 23 + 22) more days by inserting two extraordinary intercalary months between November and December. These months are called Intercalaris Prior and Intercalaris Posterior in letters of Cicero written at the time; there is no basis for the statement sometimes seen that they were called "Unodecember" and "Duodecember". Their individual lengths are unknown, as is the position of the Nones and Ides within them. Because 46 BC was the last of a series of irregular years, this extra-long year was, and is, referred to as the "last year of confusion". The first year of operation of the new calendar was 45 BC.

The Julian months were formed by adding ten days to a regular pre-Julian Roman year of 355 days, creating a regular Julian year of 365 days: Two extra days were added to Ianuarius, Sextilis (Augustus) and December, and one extra day was added to Aprilis, Iunius, September and November, setting the lengths of the months to the values they still hold today:


Lengths before 45 BC

Lengths as of 45 BC





28 (leap years: 23 or 24)

28 (leap years: 29)













Quintilis (Iulius)



Sextilis (Augustus)
















0 (leap years: 27)

(inserted between the shortened

February and March)


Macrobius states that the extra days were added immediately before the last day of each month to avoid disturbing the position of the established Roman fasti (days prescribed for certain events) relative to the start of the month. However, since Roman dates after the Ides of the month counted down toward the start of the next month, the extra days had the effect of raising the initial value of the count of the day after the Ides. Romans of the time born after the Ides of a month responded differently to the effect of this change on their birthdays. Mark Antony kept his birthday on the 14th day of Ianuarius, which changed its date from a.d. XVII Kal. Feb. to a.d. XIX Kal. Feb., a date that had previously not existed. Livia kept the date of her birthday unchanged at a.d. III Kal. Feb., which moved it from the 28th to the 30th day of Ianuarius, a day that had previously not existed. Augustus kept his on the 23rd day of September, but both the old date (a.d. VIII Kal. Oct.) and the new (a.d. IX Kal. Oct.) were celebrated in some places.

The old intercalary month was abolished. The new leap day was dated as ante diem bis sextum Kalendas Martias, usually abbreviated as a.d. bis VI Kal. Mart.; hence it is called in English the bissextile day. The year in which it occurred was termed annus bissextus, in English the bissextile year.

There is debate about the exact position of the bissextile day in the early Julian calendar. The earliest direct evidence is a statement of the first century jurist Celsus, who states that there were two halves of a 48-hour day, and that the intercalated day was the "posterior" half. An inscription from A.D. 168 states that a.d. V Kal. Mart. was the day after the bissextile day. The 19th century chronologist Ideler argued that Celsus used the term "posterior" in a technical fashion to refer to the earlier of the two days, which requires the inscription to refer to the whole 48-hour day as the bissextile. Some later historians share this view. Others, following Mommsen, take the view that Celsus was using the ordinary Latin (and English) meaning of "posterior". A third view is that neither half of the 48-hour "bis sextum" was originally formally designated as intercalated, but that the need to do so arose as the concept of a 48-hour day became obsolete.

There is no doubt that the bissextile day eventually became the earlier of the two days. In 238 Censorinus stated that it was inserted after the Terminalia (23 February) and was followed by the last five days of February, i.e. a. d. VI, V, IV, III and prid. Kal. Mart. (which would be the 24th to 28th days of February in a common year and the 25th to the 29th days in a leap year). Hence he regarded the bissextum as the first half of the doubled day. All later writers, including Macrobius about 430, Bede in 725, and other medieval computists (calculators of Easter) followed this rule, as did the liturgical calendar of the Roman Catholic Church until 1970.

During the late Middle Ages days in the month came to be numbered in consecutive day order. Consequently, the leap day was considered to be the last day in February in leap years, i.e. 29 February, which is its current position.

Leap year error

Although the new calendar was much simpler than the pre-Julian calendar, the pontifices apparently misunderstood the algorithm for leap years. They added a leap day every three years, instead of every four years. According to Macrobius, the error was the result of counting inclusively, so that the four-year cycle was considered as including both the first and fourth years. This resulted in too many leap days. Augustus remedied this discrepancy after 36 years by restoring the correct frequency. He also skipped several leap days in order to realign the year. Once this reform was completefter AD 8 at the latesthe Roman calendar was the same as the Julian proleptic calendar.

The historic sequence of leap years in this period is not given explicitly by any ancient source, although the existence of the triennial leap year cycle is confirmed by an inscription that dates from 9 or 8 BC. The chronologist Joseph Scaliger established in 1583 that the Augustan reform was instituted in 8 BC, and inferred that the sequence of leap years was 42, 39, 36, 33, 30, 27, 24, 21, 18, 15, 12, 9 BC, AD 8, 12 etc. This proposal is still the most widely accepted solution. It has sometimes been suggested that there was an additional bissextile day in the first year of the Julian reform, i.e. that 45 BC was also a leap year.

Other solutions have been proposed from time to time. Kepler proposed in 1614, on the same material used by Scaliger, that the correct sequence of leap years was 43, 40, 37, 34, 31, 28, 25, 22, 19, 16, 13, 10 BC, AD 8, 12 etc. In 1883 the German chronologist Matzat proposed 44, 41, 38, 35, 32, 29, 26, 23, 20, 17, 14, 11 BC, AD 4, 8, 12 etc., based on a passage in Dio Cassius that mentions a leap day in 41 BC that was said to be contrary to (Caesar's) rule. In the 1960s Radke argued the reform was actually instituted when Augustus became pontifex maximus in 12 BC, suggesting the sequence 45, 42, 39, 36, 33, 30, 27, 24, 21, 18, 15, 12 BC, AD 4, 8, 12 etc. With all these solutions, except that of Radke, the Roman calendar was not finally aligned to the Julian calendar of later times until 25 February (a.d. V Kal. Mar.) AD 4. On Radke's solution, the two calendars were aligned on 25 February 1 BC.

In 1999, an Egyptian papyrus was published that gives an ephemeris table for 24 BC with both Roman and Egyptian dates. The Roman dates are not aligned with any of these solutions. One suggested resolution of this problem is a fifth triennial sequence: 44, 41, 38, 35, 32, 29, 26, 23, 20, 17, 14, 11, 8 BC, AD 4, 8, 12 etc, very close to that proposed by Matzat. On this sequence the standard Julian leap year sequence began in AD 4, the 12th year of the Augustan reform, and the Roman calendar was finally aligned to the Julian calendar in 1 BC (with AD 1 the first full year of alignment), as in Radke's model. In it, the Roman year also coincided with the proleptic Julian year between 32 and 26 BC, suggesting that one aim of the realignment portion of the Augustan reform was to ensure that key dates of his career, notably the fall of Alexandria on 1 August 30 BC, were unaffected by his correction. It also places Roman dates between 45 and 32 BC as typically a day or two before the day with the same Julian date, so 1 January in the Roman calendar of the first year of the Julian reform was 31 December 46 BC (Julian date). A curious effect of this is that Caesar's assassination on the Ides (15th day) of March fell on 14 March 44 BC in the Julian calendar.

Month names

Immediately after the Julian reform, the twelve months of the Roman calendar were named Ianuarius, Februarius, Martius, Aprilis, Maius, Iunius, Quintilis, Sextilis, September, October, November, and December, just as they were before the reform. The old intercalary month, the Mensis Intercalaris, was abolished and replaced with a single intercalary day at the same point (i.e. five days before the end of Februarius). The first month of the year continued to be Ianuarius, as it had been since 153 BC.

The Romans later renamed months after Julius Caesar and Augustus, renaming Quintilis (originally, "the fifth month", with March = month 1) as Iulius (July) in 44 BC and Sextilis ("sixth month") as Augustus (August) in 8 BC. Quintilis was renamed to honour Caesar because it was the month of his birth. According to a senatus consultum quoted by Macrobius, Sextilis was renamed to honour Augustus because several of the most significant events in his rise to power, culminating in the fall of Alexandria, fell in that month.

Other months were renamed by other emperors, but apparently none of the later changes survived their deaths. Caligula renamed September ("seventh month") as Germanicus; Nero renamed Aprilis (April) as Neroneus, Maius (May) as Claudius and Iunius (June) as Germanicus; and Domitian renamed September as Germanicus and October ("eighth month") as Domitianus. At other times, September was also renamed as Antoninus and Tacitus, and November ("ninth month") was renamed as Faustina and Romanus. Commodus was unique in renaming all twelve months after his own adopted names (January to December): Amazonius, Invictus, Felix, Pius, Lucius, Aelius, Aurelius, Commodus, Augustus, Herculeus, Romanus, and Exsuperatorius.

Much more lasting than the ephemeral month names of the post-Augustan Roman emperors were the names introduced by Charlemagne. He renamed all of the months agriculturally into Old High German. They were used until the 15th century, over 700 years after his rule, and continued with some modifications until the late 18th century in Germany and in the Netherlands. The names (January to December) were: Wintarmanoth (winter month), Hornung (the month when the male red deer sheds its antlers), Lentzinmanoth (Lent month), Ostarmanoth (Easter month), Wonnemanoth (love-making month), Brachmanoth (plowing month), Heuvimanoth (hay month), Aranmanoth (harvest month), Witumanoth (wood month), Windumemanoth (vintage month), Herbistmanoth (autumn/harvest month), and Heilagmanoth (holy month).

The original Roman names as fixed in 8 BC are still in use in North Africa, where Berber farmers use the Julian calendar in everyday life. They are pronounced today Yennair, Febrair, Mars, Ibril, Mai, Yuniu, Yulius, Ghusht, Shutambir, Ktuber, Nuwambir, Dujanbir, with local variations; they are also used often in classic Arabic and medieval Arabic texts when referring to the months of the solar calendar.

Year numbering

The dominant method that the Romans used to identify a year for dating purposes was to name it after the two consuls who took office in it. Since 153 BC, they had taken office on 1 January, and Julius Caesar did not change the beginning of the year. Thus this consular year was an eponymous or named year. In addition to consular years, the Romans sometimes used the regnal year of the emperor, and by the late fourth century documents were also being dated according to the 15-year cycle of the indiction. In 537, Justinian required that henceforth the date must include the name of the emperor and his regnal year, in addition to the indiction and the consul, while also allowing the use of local eras.

In 309 and 310, and from time to time thereafter, no consuls were appointed. When this happened, the consular date was given a count of years since the last consul (so-called "post-consular" dating). After 541, only the reigning emperor held the consulate, typically for only one year in his reign, and so post-consular dating became the norm. Similar post-consular dates were also known in the West in the early 6th century. The system of consular dating, long obsolete, was formally abolished in the law code of Leo VI, issued in 888.

Only rarely did the Romans number the year from the founding of the city (of Rome), ab urbe condita (AUC). This method was used by Roman historians to determine the number of years from one event to another, not to date a year. Different historians had several different dates for the founding. The Fasti Capitolini, an inscription containing an official list of the consuls which was published by Augustus, used an epoch of 752 BC. The epoch used by Varro, 753 BC, has been adopted by modern historians. Indeed, Renaissance editors often added it to the manuscripts that they published, giving the false impression that the Romans numbered their years. Most modern historians tacitly assume that it began on the day the consuls took office, and ancient documents such as the Fasti Capitolini which use other AUC systems do so in the same way. However, Censorinus, writing in the 3rd century AD, states that, in his time, the AUC year began with the Parilia, celebrated on 21 April, which was regarded as the actual anniversary of the foundation of Rome. Because the festivities associated with the Parilia conflicted with the solemnity of Lent, which was observed until the Saturday before Easter Sunday, the early Roman church did not celebrate Easter after 21 April.

While the Julian reform applied originally to the Roman calendar, many of the other calendars then used in the Roman Empire were aligned with the reformed calendar under Augustus. This led to the adoption of several local eras for the Julian calendar, such as the Era of Actium and the Spanish Era, some of which were used for a considerable time. Perhaps the best known is the Era of Martyrs, sometimes also called Anno Diocletiani (after Diocletian), which was often used by the Alexandrian Christians to number their Easters during the 4th and 5th centuries, and continues to be used by the Coptic and Ethiopian churches, as well as influencing the modern Ethiopian calendar.

In the Eastern Mediterranean, the efforts of Christian chronographers such as Annianus of Alexandria to date the Biblical creation of the world led to the introduction of Anno Mundi eras based on this event. The most important of these was the Etos Kosmou, used throughout the Byzantine world from the 10th century and in Russia until 1700. In the West, Dionysius Exiguus proposed the system of Anno Domini in 525. This era gradually spread through the western Christian world, once the system was adopted by Bede.

New Year's Day

The Roman calendar began the year on 1 January, and this remained the start of the year after the Julian reform. However, even after local calendars were aligned to the Julian calendar, they started the new year on different dates. The Alexandrian calendar in Egypt started on 29 August (30 August after an Alexandrian leap year). Several local provincial calendars were aligned to start on the birthday of Augustus, 23 September. The indiction caused the Byzantine year, which used the Julian calendar, to begin on 1 September; this date is still used in the Eastern Orthodox Church for the beginning of the liturgical year. When the Julian calendar was adopted in AD 988 by Vladimir I of Kiev, the year was numbered Anno Mundi 6496, beginning on 1 March, six months after the start of the Byzantine Anno Mundi year with the same number. In 1492 (AM 7000), Ivan III, according to church tradition, realigned the start of the year to 1 September, so that AM 7000 only lasted for six months in Russia, from 1 March to 31 August 1492.

During the Middle Ages 1 January retained the name New Year's Day (or an equivalent name) in all Western European countries (affiliated with the Roman Catholic Church), since the medieval calendar continued to display the months from January to December (in twelve columns containing 28 to 31 days each), just as the Romans had. However, most of those countries began their numbered year on 25 December (the Nativity of Jesus), 25 March (the Incarnation of Jesus), or even Easter, as in France (see the Liturgical year article for more details).

In England, even before 1752, 1 January was sometimes treated as the start of the new year for example by Pepys while the "year starting 25th March was called the Civil or Legal Year". To reduce misunderstandings on the date, it was not uncommon in parish registers for a new year heading after 24 March, for example 1661, to have another heading at the end of the following December indicating "1661/62". This was to explain to the reader that the year was 1661 Old Style and 1662 New Style.

Most Western European countries shifted the first day of their numbered year to 1 January while they were still using the Julian calendar, before they adopted the Gregorian calendar, many during the 16th century. The following table shows the years in which various countries adopted 1 January as the start of the year. Eastern European countries, with populations showing allegiance to the Orthodox Church, began the year on 1 September from about 988.


Year starting

1 January

Adoption of

new calendar

Republic of Venice



Holy Roman Empire



Spain, Portugal



Prussia, Denmark/Norway









Southern Netherlands






Holland, Zeeland



Dutch Republic except

Holland and Zeeland












British Empire excluding Scotland






Debunked theory on month lengths

The Julian reform set the lengths of the months to their modern values. However, a 13th century scholar, Sacrobosco, proposed a different explanation for the lengths of Julian months which is still widely repeated but is certainly wrong. According to Sacrobosco, the original scheme for the months in the Julian calendar was very regular, alternately long and short. From January through December, the month lengths according to Sacrobosco for the Roman Republican calendar were:

30, 29, 30, 29, 30, 29, 30, 29, 30, 29, 30, 29.

He then thought that Julius Caesar added one day to every month except February, a total of 11 more days, giving the year 365 days. A leap day could now be added to the extra short February:

31, 29/30, 31, 30, 31, 30, 31, 30, 31, 30, 31, 30.

He then said Augustus changed this to:

31, 28/29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31

so that the length of Augustus would not be shorter than (and therefore inferior to) the length of Iulius, giving us the irregular month lengths which are still in use.

There is abundant evidence disproving this theory. First, a wall painting of a Roman calendar predating the Julian reform has survived, which confirms the literary accounts that the months were already irregular before Julius Caesar reformed them:

29, 28, 31, 29, 31, 29, 31, 29, 29, 31, 29, 29.

Also, the Julian reform did not change the dates of the Nones and Ides. In particular, the Ides were late (on the 15th rather than 13th) in March, May, July and October, showing that these months always had 31 days in the Roman calendar, whereas Sacrobosco's theory requires that March, May and July were originally 30 days long and that the length of October was changed from 29 to 30 days by Caesar and to 31 days by Augustus. Further, Sacrobosco's theory is explicitly contradicted by the 3rd and 5th century authors Censorinus and Macrobius, and it is inconsistent with seasonal lengths given by Varro, writing in 37 BC, before the Augustan reform, with the 31-day Sextilis given by the new Egyptian papyrus from 24 BC, and with the 28-day February shown in the Fasti Caeretani, which is dated before 12 BC.

From Julian to Gregorian

Main article: Gregorian calendar

The Julian calendar was in general use in Europe and Northern Africa from the times of the Roman Empire until 1582, when Pope Gregory XIII promulgated the Gregorian calendar. Reform was required because too many leap days are added with respect to the astronomical seasons on the Julian scheme. On average, the astronomical solstices and the equinoxes advance by about 11 minutes per year against the Julian year. As a result, the calculated date of Easter gradually moved out of phase with the March equinox. While Hipparchus and presumably Sosigenes were aware of the discrepancy, although not of its correct value, it was evidently felt to be of little importance at the time of the Julian reform. However, it accumulated significantly over time: the Julian calendar gained a day about every 134 years. By 1582, it was ten days out of alignment from where it supposedly was in 325 during the Council of Nicaea.

The Gregorian calendar was soon adopted by most Catholic countries (e.g. Spain, Portugal, Poland, most of Italy). Protestant countries followed later, and the countries of Eastern Europe adopted the "new calendar" even later. In the British Empire (including the American colonies), Wednesday 2 September 1752 was followed by Thursday 14 September 1752. For 12 years from 1700 Sweden used a modified Julian calendar, and adopted the Gregorian calendar in 1753, but Russia remained on the Julian calendar until 1918 (1 February 1918 became 14 February), after the Russian Revolution (which is thus called the "October Revolution" though it occurred in Gregorian November), while Greece continued to use it until 1924. During this time the Julian calendar continued to diverge from the Gregorian. In 1700 the difference became 11 days; in 1800, 12; and in 1900, 13, where it will stay until 2100.

Eastern Orthodox usage

Russian icon of the Theophany (6 January), the highest-ranked feast which occurs on the fixed cycle of the Eastern Orthodox liturgical calendar.

Although all Eastern Orthodox countries (most of them in Eastern or Southeastern Europe) had adopted the "new calendar" by 1927, their national churches had not. The "New Calendar" was proposed during a synod in Constantinople in May 1923, consisting of a solar part which was and will be identical to the Gregorian calendar until the year 2800, and a lunar part which calculated Pascha (Easter) astronomically at Jerusalem. All Orthodox churches refused to accept the lunar part, so almost all Orthodox churches continue to celebrate Pascha according to the Julian calendar (with the exception of the Estonian Orthodox Church and the Finnish Orthodox Church which are permitted to observe the Gregorian Easter).

The solar part of the new calendar was accepted by only some Orthodox churches. Those that did accept it, with hope for improved dialogue and negotiations with the Western denominations, were the Ecumenical Patriarchate of Constantinople, the Patriarchates of Alexandria, Antioch, the Orthodox Churches of Greece, Cyprus, Romania, Poland, Bulgaria (the last in 1963), and the Orthodox Church in America (although some OCA parishes are permitted to use the Julian calendar). Thus these churches celebrate the Nativity on the same day that Western Christians do, 25 December Gregorian until 2800. The Orthodox Churches of Jerusalem, Russia, Serbia, Georgia, Ukraine, and the Greek Old Calendarists and other groups continue to use the Julian calendar, thus they celebrate the Nativity on 25 December Julian (which is 7 January Gregorian until 2100). The Russian Orthodox Church has some parishes in the West which celebrate the Nativity on 25 December Gregorian. Parishes of the Orthodox Church in America Bulgarian Diocese, both before and after the 1976 transfer of that diocese from the Russian Orthodox Church Outside Russia to the Orthodox Church in America, were permitted to use the 25 December Gregorian date. Some Old Calendarist groups which stand in opposition to the state churches of their homelands will use the Great Feast of the Theophany (6 January Julian/19 January Gregorian) as a day for religious processions and the Great Blessing of Waters, to publicize their cause.

The Oriental Orthodox Churches generally use the local calendar of their homelands. However when calculating the Nativity Feast most observe the Julian calendar. This was traditionally for the sake of unity throughout Christendom. In the West, some Oriental Orthodox Churches either use the Gregorian calendar or are permitted to observe the Nativity according to it. The Armenian Apostolic Orthodox Church celebrates the Nativity as part of the Feast of Theophany according to its traditional calendar.

Berber calendar

In Northern Africa, the Julian calendar (the Berber calendar) is still in use for agricultural purposes, and is called fellh "peasant" or acjam "not Arabic". The first of yennayer currently corresponds to 14 January and will do so until 2100.

See also


Conversion between Julian and Gregorian calendars

Dominical letter


Julian day

Julian year (astronomy)

Mixed-style date

Revised Julian calendar



^ See Miriam Nancy Shields, "The new calendar of the Eastern churches", Popular Astronomy 32 (1924) 407-411 (page 411). This is a translation of M. Milankovitch, "The end of the Julian calendar and the new calendar of the Eastern churches", Astronomische Nachrichten No. 5279 (1924).

^ Luhl Fr L, The Proposal for a Common Date to Celebrate Pascha and Easter (Orthodox Christian Center).

^ Towards a Common Date of Easter. (510 March). World Council of Churches/Middle East Council of Churches Consultation, Aleppo, Syria.

^ Blackburn, B. & Holford-Strevens, L. The Oxford Companion to the Year. Oxford University press, 1999, reprinted with corrections, 2003. p. 669-70.

^ a b c d e The letter J was not invented until the 16th century.

^ W. Sternkopf, "Das Bissextum", (JCP 41 (1895) 718733) available at .

^ Nautical Almanac Offices of the United Kingdom and the United States. (1961). Explanatory Supplement to the Ephemeris London: Her Majesty's Stationery Office. p. 4101.

^ Chris Bennett, A.U.C. 709 = 45 B.C. (triennial leap year cycle)

^ A R Jones, "Calendrica II: Date Equations from the Reign of Augustus", ZPE 129 (2000) 159-166, available at

^ Chris Bennett,A.U.C. 730 = 24 B.C. (Egyptian papyrus), see also C J Bennett, "The Early Augustan Calendars in Rome and Egypt" ZPE 142 (2003) 221-240 and "The Early Augustan Calendars in Rome and Egypt:Addenda et Corrigenda" ZPE 147 (2004) 165-168.

^ Chronography of AD 354

^ Charles W. Jones, "Development of the Latin Ecclesiastical calendar", Bedae Opera de Temporibus (1943), 1122, p.28.

^ (Calendar history in Russia and in the USSR)

^, Pepys Diary "I sat down to end my journell for this year, ..."

^ Spathaky, Mike Old Style New Style dates and the change to the Gregorian calendar.

^ Spathaky, Mike Old Style New Style dates and the change to the Gregorian calendar. "An oblique stroke is by far the most usual indicator, but sometimes the alternative final figures of the year are written above and below a horizontal line, as in a fraction (a form which cannot easily be reproduced here in ASCII text). Very occasionally a hyphen is used, as 1733-34."

^ John J. Bond, "Commencement of the Year", Handy-book of rules and tables for verifying dates with the Christian era, (London: 1875), 91101.

^ Mike Spathaky Old Style and New Style Dates and the change to the Gregorian Calendar: A summary for genealogists

^ The source has Germany, whose current area during the sixteenth century was a major part of the Holy Roman Empire, a religiously divided confederation. The source is unclear as to whether all or only parts of the country made the change. In general, Roman Catholic countries made the change a few decades before Protestant countries did.

^ Sweden's conversion is complicated and took much of the first half of the 18th century. See Swedish calendar.

^ Per decree of 16 June 1575. Hermann Grotefend, "Osteranfang" (Easter beginning), Zeitrechnung de Deutschen Mittelalters und der Neuzeit (Chronology of the German Middle Ages and modern times) (18911898)

^ 1751 in England only lasted from 25 March to 31 December. The following dates 1 January to 24 March which would have concluded 1751 became part of 1752 when the beginning of the numbered year was changed from 25 March to 1 January.

^ Roscoe Lamont, "The Roman calendar and its reformation by Julius Caesar", Popular Astronomy 27 (1919) 583595. Sacrobosco's theory is discussed on pages 585587.

^ Roman Republican calendar

^ Nautical almanac offices of the United Kingdom and United States, Explanatory Supplement to the Astronomical Ephemeris and the American Ephemeris and Nautical Almanac (London: Her Majesty's Stationery Office, 1961), 4136.

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Categories: Julian calendar | Roman calendar | Julius CaesarHidden categories: All articles with unsourced statements | Articles with unsourced statements from May 2009 | Articles with unsourced statements from January 2008 | Articles with unsourced statements from January 2010

Gibbon's Decline and Fall of the Roman Empire Chapter 3 Part 3: Hadrian and Antoninus

Antoninus Pius |Rare Coins, Commemorative Coins, Gold Coins, Silver Coins, Foreign Currency and More!

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AJS Antoninus Pius AD 138 161 Silver Denarius Annona XI
AJS Antoninus Pius AD 138 161 Silver Denarius Annona XI
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HIGH QUALITY Silver Denarius Roman Coin of Antoninus Pius DAILY WAGE Certified
HIGH QUALITY Silver Denarius Roman Coin of Antoninus Pius DAILY WAGE Certified
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Antoninus Pius AD 138 161  Sestertius Aequitas
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AJS Antoninus Pius 138 161 AD SILVER Denarius Struck 140 144 AD AEQUITAS
AJS Antoninus Pius 138 161 AD SILVER Denarius Struck 140 144 AD AEQUITAS
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AD 138 139 Roman Antoninus ANACS Pius AD 138 161 Denarius Rome F 15 Corroded
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Ancient Roman Coin Bronze Sestertius of Antoninus Pius Minted 158 159 AD
Ancient Roman Coin Bronze Sestertius of Antoninus Pius Minted 158 159 AD
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Roman AS or Dupondius Antoninus Pius
Roman AS or Dupondius Antoninus Pius
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Antoninus Pius AD 138 161  Sestertius Libertas
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Antoninus Pius  Sestertius RIC 717a
Antoninus Pius Sestertius RIC 717a
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Antoninus Pius 138 161 AD  Sestertius 32mm 22g Very Rare Countermark AV Sicyily
Antoninus Pius 138 161 AD Sestertius 32mm 22g Very Rare Countermark AV Sicyily
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Antoninus Pius 138 161 AD  Sestertius Platform type
Antoninus Pius 138 161 AD Sestertius Platform type
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Roman Empire Coin Silver Denarius of Antoninus Pius NGC XF 138 161 AD
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FAUSTINA Senior Wife of Antoninus Pius DENARIUS AETERNITAS Juno
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Antoninus Pius AR Denarius 278gr18mm laureate head right Annona standing
Antoninus Pius AR Denarius 278gr18mm laureate head right Annona standing
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ANTONINUS PIUS AE 26mm Tyche minted Laodicea ad Mare Syria 140 145 AD
ANTONINUS PIUS AE 26mm Tyche minted Laodicea ad Mare Syria 140 145 AD
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EGYPT Alexandria Antoninus Pius AD 138 161  Drachm Griffin
EGYPT Alexandria Antoninus Pius AD 138 161 Drachm Griffin
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