Julian calendar Warning: You are not logged in. Your IP address will be publicly visible if you make any edits. If you log in or create an account, your edits will be attributed to your username, along with other benefits.Anti-spam check. Do not fill this in! == Leap year error == <!-- Linked from Roman calendar: Later reforms --> Although the new calendar was much simpler than the pre-Julian calendar, the pontifices initially added a leap day every three years, instead of every four. There are accounts of this in Solinus,<ref>Gaius Julius Solinus, ''De mirabilibus mundi'', c.3, available at [https://books.google.com/books?id=ABxNAAAAcAAJ].</ref> Pliny,<ref>Gaius Plinius Secundus, ''Natural History'', Vol. 2, 18.57, tr. J Bostock and H T Riley, London 1855, available at [https://www.perseus.tufts.edu/hopper/text?doc=Plin.+Nat.+18.57&fromdoc=Perseus%3Atext%3A1999.02.0137].</ref> Ammianus,<ref>''The Roman History of Ammianus Marcellinus'', 26.10, Loeb Classical Library vol. II, Harvard 1940, available at [https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Ammian/26*.html].</ref> Suetonius,<ref>Gaius Suetonius Tranquillus, ''Life of Julius Caesar'', 40.1, Loeb Classical Library, Harvard 1913, available at [https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Suetonius/12Caesars/Julius*.html#ref38] {{Webarchive|url=https://archive.today/20120530163202/http://penelope.uchicago.edu/Thayer/E/Roman/Texts/Suetonius/12Caesars/Julius*.html#ref38|date=2012-05-30}}.</ref> and Censorinus.<ref>Censorinus, ''The Natal Day'', 20.30, tr. William Maude, New York 1900 available at [http://elfinspell.com/ClassicalTexts/Maude/Censorinus/DeDieNatale-Part2.html#chap9].</ref> Macrobius<ref>Macrobius Ambrosius Theodosius, ''Saturnalia'', 1.14.13–1.14.14, tr. Percival Vaughan Davies, New York 1969, Latin text at [https://penelope.uchicago.edu/Thayer/L/Roman/Texts/Macrobius/Saturnalia/1*.html#14.13.]</ref> gives the following account of the introduction of the Julian calendar: {{blockquote|text=Caesar's regulation of the civil year to accord with his revised measurement was proclaimed publicly by edict, and the arrangement might have continued to stand had not the correction itself of the calendar led the priests to introduce a new error of their own; for they proceeded to insert the intercalary day, which represented the four quarter-days, at the beginning of each fourth year instead of at its end, although the intercalation ought to have been made at the end of each fourth year and before the beginning of the fifth. This error continued for thirty-six years by which time twelve intercalary days had been inserted instead of the number actually due, namely nine. But when this error was at length recognised, it too was corrected, by an order of Augustus, that twelve years should be allowed to pass without an intercalary day, since the sequence of twelve such years would account for the three days which, in the course of thirty-six years, had been introduced by the premature actions of the priests.}} So, according to Macrobius, # the year was considered to begin after the Terminalia (23 February),<ref>Marcus Terentius Varro, ''On the Latin Language'', 6.13, tr. Roland Kent, London 1938 available at [https://ryanfb.github.io/loebolus-data/L333.pdf].</ref> # the calendar was operated correctly from its introduction on 1 January 45 BC until the beginning of the fourth year (February 42 BC) at which point the priests inserted the first intercalation, # Caesar's intention was to make the first intercalation at the beginning of the fifth year (February 41 BC), # the priests made a further eleven intercalations after 42 BC at three-year intervals so that the twelfth intercalation fell in 9 BC, # had Caesar's intention been followed there would have been intercalations every four years after 41 BC, so that the ninth intercalation would have been in 9 BC, # after 9 BC, there were twelve years without [[leap year]]s, so that the leap days Caesar would have had in 5 BC, 1 BC and AD 4 were omitted and # after AD 4 the calendar was operated as Caesar intended, so that the next leap year was AD 8 and then leap years followed every fourth year thereafter.<ref>Nautical Almanac Offices of the United Kingdom and the United States. (1961). ''Explanatory Supplement to the Astronomical Ephemeris and the American Ephemeris and Nautical Almanac'', London: Her Majesty's Stationery Office. p. 410–11.</ref> Some people have had different ideas as to how the leap years went. The above scheme is that of Scaliger (1583) in the table below. He established that the Augustan reform was instituted in 8 BC. The table below shows for each reconstruction the implied proleptic Julian date for the first day of Caesar's reformed calendar and the first Julian date on which the Roman calendar date matches the Julian calendar after the completion of Augustus' reform. {|class="wikitable" |- ! Scholar !! Date !! Triennial leap years (BC) !! First<br> Julian day !! First<br> aligned day !! Quadriennial<br> leap year<br> resumes |- | Bennett<ref>C. J. Bennett, "The Early Augustan Calendars in Rome and Egypt", Zeitschrift fűr Papyrologie und Epigraphik 142 (2003) 221–240 and "The Early Augustan Calendars in Rome and Egypt: Addenda et Corrigenda", Zeitschrift fűr Papyrologie und Epigraphik 147 (2004) 165–168; see also Chris Bennett, [https://web.archive.org/web/20120219041722/https://tyndalehouse.com/Egypt/ptolemies/chron/roman/024bc.htm A.U.C. 730 = 24 B.C. (Egyptian papyrus)].</ref> | 2003 | 44, 41, 38, 35, 32, 29, 26, 23, 20, 17, 14, 11, 8 || 31 December 46 BC || 25 February 1 BC || AD 4 |- | Soltau<ref>W. Soltau, [https://books.google.com/books?id=dVs-AAAAYAAJ&pg=PA170 ''Römische Chronologie''] (Freiburg, 1889) 170–173. He accepted Matzat's phase of the triennial cycle but argued that it was absurd to suppose that Caesar would have made the second Julian year a leap year and that the 36 years had to be accounted from 45 BC.</ref> | 1889 | 45, 41, 38, 35, 32, 29, 26, 23, 20, 17, 14, 11 || 2 January 45 BC || 25 February AD 4 || AD 8 |- | Matzat<ref>H. Matzat, [https://archive.org/details/rmischechronolo02matzgoog/page/n197 <!-- pg=13 --> ''Römische Chronologie'' I] (Berlin, 1883), 13–18. His argument rested on [https://penelope.uchicago.edu/Thayer/E/Roman/Texts/Cassius_Dio/48*.html#33.4 Dio Cassius 48.33.4] which mentions a leap day inserted in 41 BC, "contrary to the (i.e., Caesar's) rule", in order to avoid having a market day on the first day of 40 BC. Dio stated that this leap day was compensated for "later". Matzat proposed this was done by omitting a scheduled leap day in 40 BC, rather than by omitting a day from an ordinary year.</ref> | 1883 | 44, 41, 38, 35, 32, 29, 26, 23, 20, 17, 14, 11 || 1 January 45 BC || 25 February 1 BC || AD 4 |- | [[Ludwig Ideler|Ideler]]<ref>C. L. Ideler, [https://books.google.com/books?id=ql56SzvCeJMC&pg=PA130 ''Handbuch der mathematischen und technischen Chronologie''] (Berlin, 1825) II 130–131. He argued that Caesar would have enforced the bissextile day by introducing it in his first reformed year. T. E. Mommsen, [https://archive.org/details/bub_gb_qsspAAAAYAAJ/page/n281 <!-- pg=282 --> ''Die Römische Chronologie bis auf Caesar''] (Berlin, 1859) 282–299, provided additional circumstantial arguments.</ref> | 1825 | 45, 42, 39, 36, 33, 30, 27, 24, 21, 18, 15, 12, 9 || 1 January 45 BC || 25 February AD 4 || AD 8 |- | [[Johannes Kepler|Kepler]]<ref>J. Kepler, ''De Vero Anno Quo Æternus Dei Filius Humanan Naturam in Utero Benedictæ Virginis Mariæ Assumpsit'' (Frankfurt, 1614) Cap. V, repub. in F. Hammer (ed.), ''Johannes Keplers Gesammelte Werke'' (Berlin, 1938) V 28.</ref> | 1614 | 43, 40, 37, 34, 31, 28, 25, 22, 19, 16, 13, 10 || 2 January 45 BC || 25 February AD 4 || AD 8 |- | [[Thomas Harriot|Harriot]]<ref name="Harriot" /> | After 1610 | 43, 40, 37, 34, 31, 28, 25, 22, 19, 16, 13, 10 || 1 January 45 BC || 25 February 1 BC || AD 4 |- | [[Heinrich Bünting|Bünting]]<ref name="Harriot">For the list of triennial leap years proposed by Bünting, Christmann and Harriot, see [http://www.hermetic.ch/cal_stud/cassidy/shspk1zc.pdf Harriot's comparative table reproduced by Simon Cassidy] (Fig. 6). The table numbers years as Julian years, where Julian year 1 = 45 BC. Thus, Scaliger and Clavius (col. 7) resume intercalation in Julian year 53 = AD 8, while Bünting (col. 8) and Harriot (col. 3) resume it in Julian year 49 = AD 4 and Christmann (col. 9) in year 52 = AD 7.</ref> | 1590 | 45, 42, 39, 36, 33, 30, 27, 24, 21, 18, 15, 12 || 1 January 45 BC || 25 February 1 BC || AD 4 |- | [[Jakob Christmann|Christmann]]<ref name="Harriot" /><ref>J. Christmann [https://books.google.com/books?id=NTc6AAAAcAAJ&pg=PA173 ''Muhamedis Alfragani arabis chronologica et astronomica elementa''] (Frankfurt, 1590), 173. His argument assumed that the triennial cycle started in the third Julian year.</ref> | 1590 | 43, 40, 37, 34, 31, 28, 25, 22, 19, 16, 13, 10 || 2 January 45 BC || 25 February AD 4 || AD 7<ref name="Harriot" /> |- | [[Joseph Scaliger|Scaliger]]<ref>J. J. Scaliger, ''De emendatione temporum'' (Paris, 1583), 159, 238.</ref> | 1583 | 42, 39, 36, 33, 30, 27, 24, 21, 18, 15, 12, 9 || 2 January 45 BC || 25 February AD 4 || AD 8 |} By the systems of Scaliger, Ideler and Bünting, the leap years prior to the suspension happen to be BC years that are divisible by 3, just as, after leap year resumption, they are the AD years divisible by 4. Pierre Brind'Amour<ref>Pierre Brind'Amour, ''Le calendrier romain'', Ottawa 1983, pp. 45–46.</ref> argued that "only one day was intercalated between 1/1/45 and 1/1/40 (disregarding a momentary 'fiddling' in December of 41)<ref>Dio Cassius 48.33.4, tr. Earnest Cary, Loeb Classical Library, 9 vol., Harvard 1914–1927, available at [https://penelope.uchicago.edu/Thayer/L/Roman/Texts/Cassius_Dio/48*.html#33.4].</ref> to avoid the nundinum falling on Kal. Ian."<ref>Refutation of Brind'Amour's theory by John Ward, ''Re: Intercalation in 45BC to 8AD'', East Carolina University Calendar discussion List CALNDR-L, April 1998.</ref> Alexander Jones says that the correct Julian calendar was in use in Egypt in 24 BC,<ref name="papyrus" /> implying that the first day of the reform in both Egypt and Rome, {{nowrap|1 January 45 BC}}, was the Julian date 1 January if 45 BC was a leap year and 2 January if it was not. This necessitates fourteen leap days up to and including AD 8 if 45 BC was a leap year and thirteen if it was not. In 1999, a papyrus was discovered which gives the dates of astronomical phenomena in 24 BC in both the Egyptian and Roman calendars. From {{nowrap|30 August 26 BC (Julian)}}, Egypt had two calendars: the old Egyptian in which every year had 365 days and the new Alexandrian in which every fourth year had 366 days. Up to {{nowrap|28 August 22 BC (Julian)}} the date in both calendars was the same. The dates in the Alexandrian and Julian calendars are in one-to-one correspondence except for the period from 29 August in the year preceding a Julian leap year to the following 24 February.<ref>Dieter Hagedorn, ''Zum aegyptischen Kalender unter Augustus'', Zeitschrift fűr Papyrologie und Epigraphik 100 (1994) 211–222, available at [http://www.uni-koeln.de/phil-fak/ifa/zpe/downloads/1994/100pdf/100211.pdf].</ref> From a comparison of the astronomical data with the Egyptian and Roman dates, Alexander Jones<ref name="papyrus">Alexander Jones, ''Calendrica II: Date Equations from the Reign of Augustus'', Zeitschrift fűr Papyrologie und Epigraphik 129 (2000) 159–166, available at [http://www.uni-koeln.de/phil-fak/ifa/zpe/downloads/2000/129pdf/129159.pdf].</ref> concluded that the Egyptian astronomers (as opposed to travellers from Rome) used the correct Julian calendar. Due to the confusion about this period, we cannot be sure exactly what day (e.g. [[Julian day number]]) any particular Roman date refers to before March of 8 BC, except for those used in Egypt in 24{{nbsp}}BC which are secured by astronomy. An inscription has been discovered which orders a [[Paullus Fabius Maximus#A New Calendar in the Province of Asia|new calendar]] to be used in the [[Province of Asia]] to replace the previous Greek lunar calendar.<ref>[http://epigraphy.packhum.org/inscriptions/main?url=oi%3Fikey%3D252886%26region%3D8%26subregion%3D29%26bookid%3D520%26caller%3Dsearch%26start%3D1193%26end%3D1202 OGIS 458] (Greek).</ref> According to one translation {{Blockquote|text=Intercalation shall commence on the day after 14 Peritius [a.d. IX Kal. Feb, which would have been 15 Peritius] as it is currently constituted in the third year following promulgation of the decree. Xanthicus shall have 32 days in this intercalary year.<ref>B A Buxton and R Hannah in ''Studies in Latin Literature and Roman History'' (ed. C Deroux), XII 290.</ref> }} This is historically correct. It was decreed by [[Paullus Fabius Maximus|the proconsul]] that the first day of the year in the new calendar shall be Augustus' birthday, a.d. IX Kal. Oct. Every month begins on the ninth day before the kalends. The date of introduction, the day after 14 Peritius, was 1 Dystrus, the next month. The month after that was Xanthicus. Thus Xanthicus began on a.d. IX Kal. Mart., and normally contained 31 days. In leap year, however, it contained an extra "Sebaste day", the Roman leap day, and thus had 32 days. From the lunar nature of the old calendar we can fix the starting date of the new one as 24 January, {{nowrap|a.d. IX Kal. Feb 5 BC}} in the Julian calendar, which was a leap year. Thus from inception the dates of the reformed Asian calendar are in one-to-one correspondence with the Julian. Another translation of this inscription is {{Blockquote|Intercalation shall commence on the day after the fourteenth day in the current month of Peritius [a.d. IX Kal. Feb], occurring every third year. Xanthicus shall have 32 days in this intercalary year.<ref>U. Laffi, "Le iscrizioni relative all'introduzione nel 9 a.c. del nuovo calendario della provincia d'Asia", Studi Classici e Orientali 16 (1967) 5–99.</ref>}} This would move the starting date back three years to 8 BC, and from the lunar synchronism back to 26 January (Julian). But since the corresponding Roman date in the inscription is 24 January, this must be according to the incorrect calendar which in 8 BC Augustus had ordered to be corrected by the omission of leap days. As the authors of the previous{{which|date=October 2019}} paper point out, with the correct four-year cycle being used in Egypt and the three-year cycle abolished in Rome, it is unlikely that Augustus would have ordered the three-year cycle to be introduced in Asia. Summary: Please note that all contributions to Christianpedia may be edited, altered, or removed by other contributors. If you do not want your writing to be edited mercilessly, then do not submit it here. You are also promising us that you wrote this yourself, or copied it from a public domain or similar free resource (see Christianpedia:Copyrights for details). Do not submit copyrighted work without permission! Cancel Editing help (opens in new window) Discuss this page