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Julian Calendar)
The Julian calendar was a reform of the
Roman calendar which was introduced by
Julius Caesar in 46 BC and came into force in 45 BC (709
ab urbe condita). It was chosen after consultation with
the astronomer
Sosigenes of Alexandria and was probably designed to
approximate the
tropical year, known at least since
Hipparchus. It has a regular year of 365
days
divided into 12
months, and a
leap day is added to
February every four years. Hence the Julian year is on
average 365.25 days long.
The Julian calendar remained in use into the 20th century in
some countries as a national calendar, but it has generally been
replaced by the modern Gregorian calendar. It is still used by
the
Berber people of
North Africa and by many national
Orthodox churches. Orthodox Churches no longer using the
Julian calendar typically use the
Revised Julian calendar rather than the Gregorian calendar.
The notation
"Old Style" (OS) is sometimes used to indicate a date in the
Julian calendar, as opposed to
"New Style" (NS), which either represents the Julian date
with the start of the year as
1 January or a full mapping onto the
Gregorian calendar.
[edit]
Motivation
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 becoming 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 366Ľ 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
365Ľ 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, 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, since 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, 63 to 46 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.
The reform was intended to correct this problem permanently,
by creating a calendar that remained aligned to the sun without
any human intervention.
[edit]
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 the 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,[1]
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:
Months |
Lengths before 45 BC |
Lengths after 46 BC |
Ianuarius[1] |
29 |
31 |
Februarius |
28 (23/24) |
28 (29) |
Martius |
31 |
31 |
Aprilis |
29 |
30 |
Maius |
31 |
31 |
Iunius[1] |
29 |
30 |
Quintilis (Iulius) |
31 |
31 |
Sextilis (Augustus) |
29 |
31 |
September |
29 |
30 |
October |
31 |
31 |
November |
29 |
30 |
December |
29 |
31 |
Intercalaris |
(27) |
(abolished) |
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 towards 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
originally inserted following
February 24, a.d. VI Kal. Mar. by Roman reckoning, since
this is the point at which intercalary months were inserted in
the pre-Julian calendar. It was considered as extending that day
to 48 hours, so it was dated as "a.d. VI bis Kal. Mar.", and is
called the bissextile day. During the late
Middle Ages when days in the month came to be numbered in
consecutive day order, the Leap Day was considered to be the
last day in February in leap years, i.e.
February 29.
[edit]
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.
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 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
26 February (a.d. V Kal. Mar.)
AD 4. On
Radke's solution, the two calendars were aligned on
26 February
1 BC.
In 1999, an Egyptian
papyrus was published that gives an
ephemeris table for 24 BC with both Roman and Egyptian
dates. From this it can be shown that the most likely sequence
was in fact 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. This
sequence shows that the standard Julian leap year sequence began
in AD 4, the 12th year of the Augustan reform, and that the
Roman calendar was finally aligned to the Julian calendar in 1
BC, as in Radke's model. The Roman year also coincided with the
proleptic Julian year between 32 and 26 BC. This suggests 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.
Roman dates before 32 BC were 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.
[edit]
Month names
Immediately after the Julian reform, the twelve months of the
Roman calendar were named Ianuarius,[1]
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)[1]
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, and
with some modifications until the late 18th century in Germany
and in the Netherlands (January through December):
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).
[edit]
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.[2]
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,[3]
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.
[edit]
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.[4]
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 last known post-consular date
is year 22 after the consulate of
Heraclius.[verification
needed] The last emperor to hold the
consulate was
Constans II. 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.[5]
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 continued to be used by the Coptic and
Abyssinian churches.
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
Aetos Kosmou, used throughout the Byzantine world from the
10th century and in Russia till 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.
[edit]
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
Russia 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.[6]
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 before 1752,
1 January was celebrated as the New Year festival,[7]
but the "year starting 25th March was called the Civil or Legal
Year, although the phrase
Old Style was more commonly used".[8]
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.[9]
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.
Note that as a consequence of change of New Year,
1 January
1751
to
24 March
1751
were non-existent dates in England.
[edit]
From Julian to Gregorian
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 moon. 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.
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 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 1917, after the
Russian Revolution (which is thus called the "October
Revolution" though it occurred in Gregorian November), while
Greece continued to use it until 1923. 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 till 2100.
Although all
Eastern Orthodox countries (most of them in
Eastern or
Southeastern Europe) had adopted the Gregorian calendar by
1927, their national churches had not. A
revised Julian 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 Easter
astronomically at
Jerusalem. All Orthodox churches refused to accept the lunar
part, so almost all Orthodox churches continue to celebrate
Easter according to the Julian calendar (the
Finnish Orthodox Church uses the Gregorian Easter).
The solar part of the revised Julian 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,
Macedonia,
Serbia,
Georgia,
Ukraine, and the
Greek Old Calendarists continue to use the Julian calendar
for their fixed dates, thus they celebrate the Nativity on
25 December Julian (which is
7 January Gregorian until 2100).
In Northern Africa, the Julian calendar (the
Berber calendar) is still in use for agricultural purposes,
and is called ????? fellahi "peasant" or s????? acjami
"not Arabic". The first of yennayer currently corresponds
to
January 14 and will do so until 2100.
[edit]
See also
- ^
a
b
c
d
e
The letter
J
was not invented until the 16th century.
- ^
Roscoe Lamont, "The
Roman calendar and its reformation by Julius Caesar",
Popular Astronomy 27 (1919) 583–595. The
reference is the second article in the hyperlink; its
last page is
here. Sacrobosco's theory is discussed on pages
585–587.
- ^
Roman Republican calendar
- ^
Chronography of AD 354, see
[1]
- ^
Charles W. Jones, "Development of the Latin
Ecclesiastical calendar", Bedae Opera de Temporibus
(1943), 1-122, p.28.
- ^
??????? ????????? ? ?????? ? ? ???? (Calendar history in
Russia and in the USSR)
- ^
http://www.pepysdiary.com/archive/1661/12/31/index.php,
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."
- ^
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
Gregorian calendar: Timeline for details
- ^
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)
(1891-1898)
[edit]
External links