Roman calendar
Encyclopedia
The Roman calendar changed its form several times in the time between the founding of Rome
and the fall of the Roman Empire
. This article generally discusses the early Roman or 'pre-Julian' calendar
s. The calendar used after 46 BC is discussed under Julian calendar
.
| |}>
is believed to have been a lunar calendar
, which may have been based on one of the Greek lunar calendars
. As the time between new moons averages 29.5 days, its months were constructed to be either hollow (29 days) or full (30 days). Full months were considered powerful and therefore auspicious; hollow months were unlucky. Unlike currently used dates, which are numbered sequentially from the beginning of the month, the Romans counted backwards from three fixed points: the Nones, the Ides and the Kalends of the following month. This system originated in the practice of "calling" the new month when the lunar crescent was first observed in the west after sunset. From the shape and orientation of the new moon, the number of days remaining to the nones would be proclaimed.
, the founder of Rome around 753 BC. His version contained ten month
s with the vernal equinox in the first month. However, his months were not lunar:
The calendar year lasted 304 days and there were about 61 days of winter which were not assigned to any month. The later months were named based on their position in the calendar: Quintilis comes from quinque (meaning five), Sextilis from sex (meaning six), September from septem (meaning seven), October from octo (meaning eight), November from novem (meaning nine) and December from decem (meaning ten).
, the second of the seven traditional kings of Rome, reformed the calendar
of Romulus by prefixing January and February around 713 BC to the original ten months; thus the names of Quintilis, Sextilis, September, October, November and December (implying fifth through tenth) no longer agreed with their position in his calendar.
Although Numa wanted to have a lunar year of 354 days, Romans considered odd numbers to be lucky, so Numa added 51 days to the 304 days in the calendar of Romulus and took one day from each of the six 30-day months giving a total of 57 days to share between January and February. January was given 29 days leaving February with the unlucky number of 28 days, suitable for the month of purification. Of the eleven months with an odd number of days, four had 31 days each and seven had 29 days each.
February was split into two parts, each with an odd number of days. The first part ended with the Terminalia on the 23rd, which was considered the end of the religious year; the five remaining days formed the second part. In order to keep the calendar year roughly aligned with the solar year, a leap month
(the Mensis Intercalaris, sometimes also known as Mercedonius
or Mercedinus), was added from time to time between the two parts of February. This caused the second part of February to be incorporated in the intercalary month as its last five days; there was thus no change either in their dates or the festivals observed on them. The resulting leap year was either 377 or 378 days long, depending on whether Intercalaris began on the day after the Terminalia or the second day after the Terminalia. Intercalaris had 27 days, its nones were on the fifth and its ides on the thirteenth as usual; the next following day was a.d. XV Kal. Mart.
The decision to insert the intercalary month
was the responsibility of the pontifex maximus
. On average, this happened roughly in alternate years. The system of aligning the year through intercalary months broke down at least twice: the first time was during and after the Second Punic War. It led to the reform of the Lex Acilia in 191 BC, the details of which are unclear, but it appears to have successfully regulated intercalation
for over a century. The second breakdown was in the middle of the 1st century BC and may have been related to the increasingly chaotic and adversarial nature of Roman politics at the time. The position of pontifex maximus was not a full-time job; it was held by a member of the Roman elite, who would almost invariably be involved in the machinations of Roman politics. Because a Roman calendar year defined the term of office of elected Roman magistrates, a pontifex maximus would have reason to lengthen a year in which he or his allies were in power, or shorten a year in which his political opponents held office. It was while Julius Caesar
was pontifex maximus that the calendar was overhauled, with the result being the Julian calendar
. The calendar reforms were completed during the reign of his successor Augustus
. Quintilis was renamed Iulius (July) in honour of Julius Caesar
in 44 BC and Sextilis was renamed Augustus (August) in honour of Augustus
in 8 BC.
The day preceding the Kalends, Nones, or Ides was Pridie, e.g. Prid. Id. Mart. = 14 March. Other days were a.d. NN, abbreviation for ante diem NN (meaning "on the Number, numerus of days before the Named reference day, nomen"), e.g. a.d. III Kal. Oct. = on the third day before the October Kalends = 28 September (where this date refers to the early period when September had only 29 days). The inclusive system of counting meant that the second day before the fixed point did not exist (because it was the same as Pridie, and the 'third' day was thus the day before that). Some examples: a.d. IV Non. Jan. = 2 January; a.d. VI Non. Mai. = 2 May; a.d. VIII Id. Apr. = 6 April; a.d. VIII Id. Oct. = 8 October; a.d. XVII Kal. Nov. = 16 October; a.d. XVII Kal. Dec. = 14 November (where the date refers to the early period when November had only 29 days).
Some dates are sometimes known by the name of a festival that occurred on them, or shortly afterwards. Such dates are known for the Feralia
, Quirinalia and the Terminalia (though not yet for the Lupercalia
). These dates are all after the Ides of February, which suggests that they are connected with resolving an ambiguity that could arise in intercalary years: dates of the form a.d. [N] Kal. Mart. were dates in late February in regular years but were a month later in intercalary years. However, it is much debated whether there was a fixed rule for using festival-based dates. It has been suggested that dates like a.d. X Terminalia (known from an inscription in 94 BC) indicated that the year was intercalary, that it was not intercalary, or that it could be intercalary.
When Julius Caesar
added a day to September, he added it to the end of the month, so as not to disturb the dates of religious festivals in September, but the effect was to increase the count of the day that immediately followed the Ides:
As a result, the position of all the following dates in September got bumped up by one day. This has some unexpected effects. For example, the emperor Augustus
was born on 23 September 63 BC. In the pre-Julian calendar this is eight days before the Kalends of October (or, in Roman style, a.d. VIII Kal. Oct.), but in the Julian calendar it is nine days (a.d. IX Kal. Oct.). Because of this ambiguity, his birthday was sometimes celebrated on both dates, i.e. (for us) on both 23 and 24 September.
The nundinal cycle formed one rhythm of day-to-day Roman life; the market day was the day that country people would come to the city, and the day that city people would buy their eight days' worth of groceries. For this reason, a law was passed in 287 BC (the Lex Hortensia
) that forbade the holding of meetings of the comitia (for example to hold elections) on market days, but permitted the holding of legal actions. In the late republic, a superstition arose that it was unlucky to start the year with a market day (i.e. for the market day to fall on 1 January, with a letter A), and the pontiff
s, who regulated the calendar, took steps to avoid it.
Because the nundinal cycle was absolutely fixed at eight days under the Republic, information about the dates of market days is one of the most important tools we have for working out the Julian equivalent of a Roman date in the pre-Julian calendar. In the early Empire, the Roman market day was occasionally changed. The details of this are not clear, but one likely explanation is that it would be moved by one day if it fell on the same day as the festival of Regifugium
, an event that could occur every other Julian leap year. When this happened the market day would be moved to the next day, which was the bissextile (leap) day.
The nundinal cycle was eventually replaced by the modern seven-day week
, which first came into use in Italy during the early imperial period, after the Julian calendar
had come into effect. The system of nundinal letters was also adapted for the week, see dominical letter
. For a while, the week and the nundinal cycle coexisted, but by the time the week was officially adopted by Constantine in AD 321 the nundinal cycle had fallen out of use. For further information on the week, see week
and days of the week.
. The most important of these were dies fasti, marked by an F, on which legal matters could normally be heard, dies nefasti, marked by an N, on which they could not, and dies comitiales, marked by a C, on which meetings of the public assemblies known as comitia were permitted, subject to other constraints such as the Lex Hortensia
. A few days had a different character, e.g. EN (endotercissus or perhaps endoitio exitio nefas), a day in which legal actions were permitted on half of the day only, and NP, which were public holidays.
In the Roman Republic
, the years were not counted. Instead they were named after the consul
s who were in power at the beginning of the year (see List of Republican Roman Consuls). For example, 205 BC was The year of the consulship of Publius Cornelius Scipio Africanus and Publius Licinius Crassus. Lists of consuls were maintained in the fasti
.
However, in the later Republic, historians and scholars began to count years from the founding of the city of Rome. Different scholars used different dates for this event. The date most widely used today is that calculated by Varro
, 753 BC, but other systems varied by up to several decades. Dates given by this method are numbered ab urbe condita
(meaning from the founding of the city, and abbreviated AUC). When reading ancient works using AUC dates, care must be taken to determine the epoch used by the author before translating the date into a Julian year.
The first day of the consular term, which was effectively the first day of the year, changed several times during Roman history. It became 1 January in 153 BC. Before then it was 15 March. Earlier changes are a little less certain. There is good reason to believe it was 1 May for most of the 3rd century BC, until 222 BC. Livy mentions consulates starting on 1 July before then, and arguments exist for other dates at earlier times.
in 44 BC, and this is usually converted to 15 March 44 BC. While he was indeed assassinated on the 15th day of the Roman month Martius, the equivalent date on the modern Julian calendar is probably 14 March 44 BC.
Finding the exact Julian equivalent of a pre-Julian date can be very hard. Since we have an essentially complete list of the consuls, it is not difficult to find the Julian year that generally corresponds to a pre-Julian year. However, our sources very rarely tell us which years were regular, which were intercalary, and how long an intercalary year was. Nevertheless, we do know that the pre-Julian calendar could be substantially out of alignment with the Julian calendar. Two precise astronomical synchronisms given by Livy show that in 168 BC the two calendars were misaligned by more than two months, and in 190 BC they were four months out of alignment.
We have a number of other clues to help us reconstruct the Julian equivalent of pre-Julian dates. First, we know the precise Julian date for the start of the Julian calendar (although there is some uncertainty even about that), and we have detailed sources for the previous decade or so, mostly in the letters and speeches of Cicero
. Combining these with what we know about how the calendar worked, especially the nundinal cycle, we can accurately convert Roman dates after 58 BC relative to the start of the Julian calendar. Also, the histories of Livy
give us exact Roman dates for two eclipses in 190 BC and 168 BC, and we have a few loose synchronisms to dates in other calendars which help to give rough (and sometimes exact) solutions for the intervening period. Before 190 BC the alignment between the Roman and Julian years is determined by clues such as the dates of harvests mentioned in the sources.
Combining these sources of data, we are able to estimate approximate Julian equivalents of Roman dates back to the start of the First Punic War
in 264 BC. However, while we have enough data to make such reconstructions, the number of years before 45 BC for which we can convert pre-Julian Roman dates to Julian dates with certainty is very small, and several reconstructions of the pre-Julian calendar are possible. A detailed reconstruction giving conversions from pre-Julian dates into Julian dates is available.
Founding of Rome
The founding of Rome is reported by many legends, which in recent times are beginning to be supplemented by scientific reconstructions.- Development of the city :...
and the fall of the Roman Empire
Roman Empire
The Roman Empire was the post-Republican period of the ancient Roman civilization, characterised by an autocratic form of government and large territorial holdings in Europe and around the Mediterranean....
. This article generally discusses the early Roman or 'pre-Julian' calendar
Calendar
A calendar is a system of organizing days for social, religious, commercial, or administrative purposes. This is done by giving names to periods of time, typically days, weeks, months, and years. The name given to each day is known as a date. Periods in a calendar are usually, though not...
s. The calendar used after 46 BC is discussed under Julian calendar
Julian calendar
The Julian calendar began in 45 BC as a reform of the Roman calendar by Julius Caesar. It was chosen after consultation with the astronomer Sosigenes of Alexandria and was probably designed to approximate the tropical year .The Julian calendar has a regular year of 365 days divided into 12 months...
.
History
The original Roman calendarCalendar
A calendar is a system of organizing days for social, religious, commercial, or administrative purposes. This is done by giving names to periods of time, typically days, weeks, months, and years. The name given to each day is known as a date. Periods in a calendar are usually, though not...
is believed to have been a lunar calendar
Lunar calendar
A lunar calendar is a calendar that is based on cycles of the lunar phase. A common purely lunar calendar is the Islamic calendar or Hijri calendar. A feature of the Islamic calendar is that a year is always 12 months, so the months are not linked with the seasons and drift each solar year by 11 to...
, which may have been based on one of the Greek lunar calendars
Hellenic calendar
The Hellenic calendar—or more properly, the Hellenic calendars, for there was no uniform calendar imposed upon all of Classical Greece—began in most Greek states between Autumn and Winter except the Attic calendar, which began in June...
. As the time between new moons averages 29.5 days, its months were constructed to be either hollow (29 days) or full (30 days). Full months were considered powerful and therefore auspicious; hollow months were unlucky. Unlike currently used dates, which are numbered sequentially from the beginning of the month, the Romans counted backwards from three fixed points: the Nones, the Ides and the Kalends of the following month. This system originated in the practice of "calling" the new month when the lunar crescent was first observed in the west after sunset. From the shape and orientation of the new moon, the number of days remaining to the nones would be proclaimed.
Calendar of Romulus
Roman writers claimed that their calendar was invented by RomulusRomulus and Remus
Romulus and Remus are Rome's twin founders in its traditional foundation myth, although the former is sometimes said to be the sole founder...
, the founder of Rome around 753 BC. His version contained ten month
Month
A month is a unit of time, used with calendars, which was first used and invented in Mesopotamia, as a natural period related to the motion of the Moon; month and Moon are cognates. The traditional concept arose with the cycle of moon phases; such months are synodic months and last approximately...
s with the vernal equinox in the first month. However, his months were not lunar:
| Calendar of Romulus |
|---|
| Martius March March is in present time held to be the third month of the year in both the Julian and Gregorian calendars. It is one of the seven months which are 31 days long.... (31 days) |
| April April April is the fourth month of the year in the Julian and Gregorian calendars, and one of four months with a length of 30 days. April was originally the second month of the Roman calendar, before January and February were added by King Numa Pompilius about 700 BC... is (30 days) |
| Maius (31 days) |
| Iunius Junius (month) Junius was the Latin name for the fourth month in the Roman calendar that was before Quintilis.Iunius, or Junius, is named in honor of the ancient Roman goddess Juno, the wife of Jupiter and considered the patroness of marriage. The first half of Iunius is a period of religious purification, and... (30 days) |
| Quintilis Quintilis In the 10-month calendar of ancient Rome, Quintilis follows Junius and precedes Sextilis . Quintilis is Latin for "fifth", that is, it was the fifth month in the earliest calendar attributed to Romulus, which began with the month of Martius... (31 days) |
| Sextilis Sextilis Sextilis was the original Latin name for the sixth month in the Roman calendar. It was renamed Augustus in 8 BC in honor of the first Roman emperor, Augustus Caesar, for two reasons... (30 days) |
| September September September is the 9th month of the year in the Julian and Gregorian Calendars and one of four months with a length of 30 days.September in the Southern Hemisphere is the seasonal equivalent of March in the Northern Hemisphere.... (30 days) |
| October October October is the tenth month of the year in the Julian and Gregorian Calendars and one of seven months with a length of 31 days. The eighth month in the old Roman calendar, October retained its name after January and February were inserted into the calendar that had originally been created by the... (31 days) |
| November November November is the 11th month of the year in the Julian and Gregorian Calendars and one of four months with the length of 30 days. November was the ninth month of the ancient Roman calendar... (30 days) |
| December December December is the 12th and last month of the year in the Julian and Gregorian Calendars and one of seven months with the length of 31 days.December starts on the same day as September every year and ends on the same day as April every year.-Etymology:... (30 days) |
The calendar year lasted 304 days and there were about 61 days of winter which were not assigned to any month. The later months were named based on their position in the calendar: Quintilis comes from quinque (meaning five), Sextilis from sex (meaning six), September from septem (meaning seven), October from octo (meaning eight), November from novem (meaning nine) and December from decem (meaning ten).
Calendar of Numa
Numa PompiliusNuma Pompilius
Numa Pompilius was the legendary second king of Rome, succeeding Romulus. What tales are descended to us about him come from Valerius Antias, an author from the early part of the 1st century BC known through limited mentions of later authors , Dionysius of Halicarnassus circa 60BC-...
, the second of the seven traditional kings of Rome, reformed the calendar
Calendar reform
A calendar reform is any significant revision of a calendar system. The term sometimes is used instead for a proposal to switch to a different calendar.Most calendars have several rules which could be altered by reform:...
of Romulus by prefixing January and February around 713 BC to the original ten months; thus the names of Quintilis, Sextilis, September, October, November and December (implying fifth through tenth) no longer agreed with their position in his calendar.
Although Numa wanted to have a lunar year of 354 days, Romans considered odd numbers to be lucky, so Numa added 51 days to the 304 days in the calendar of Romulus and took one day from each of the six 30-day months giving a total of 57 days to share between January and February. January was given 29 days leaving February with the unlucky number of 28 days, suitable for the month of purification. Of the eleven months with an odd number of days, four had 31 days each and seven had 29 days each.
| Civil calendar | Religious calendar | |
|---|---|---|
| according to Macrobius and Plutarch Plutarch Plutarch then named, on his becoming a Roman citizen, Lucius Mestrius Plutarchus , c. 46 – 120 AD, was a Greek historian, biographer, essayist, and Middle Platonist known primarily for his Parallel Lives and Moralia... |
according to Ovid Ovid Publius Ovidius Naso , known as Ovid in the English-speaking world, was a Roman poet who is best known as the author of the three major collections of erotic poetry: Heroides, Amores, and Ars Amatoria... (modern order due to Decemviri Decemviri Decemviri is a Latin term meaning "Ten Men" which designates any such commission in the Roman Republic... , 450 BC) |
according to Fowler William Warde Fowler William Warde Fowler was an English historian and ornithologist, and tutor at Lincoln College, Oxford. He was best known for his works on ancient Roman religion.... |
| Ianuarius Ianuarius The word "Ianuarius" is the original Roman designation of the month January.The name is either derived from the two-faced Roman god Janus, from the Latin word ianua, which means "door", or it is the masculine form of Diana, which would be Dianus or Ianus .... (29) |
Ianuarius | Martius |
| Februarius (28) | Martius | Aprilis |
| Martius (31) | Aprilis | Maius |
| Aprilis (29) | Maius | Iunius |
| Maius (31) | Iunius | Quintilis |
| Iunius (29) | Quintilis | Sextilis |
| Quintilis (31) | Sextilis | September |
| Sextilis (29) | September | October |
| September (29) | October | November |
| October (31) | November | December |
| November (29) | December | Ianuarius |
| December (29) | Februarius | Februarius |
February was split into two parts, each with an odd number of days. The first part ended with the Terminalia on the 23rd, which was considered the end of the religious year; the five remaining days formed the second part. In order to keep the calendar year roughly aligned with the solar year, a leap month
Intercalation
Intercalation 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 Mensis Intercalaris, sometimes also known as Mercedonius
Mercedonius
Mercedonius, also known as Intercalaris, was the intercalary month added in leap years of the Roman calendar. The resulting year was either 377 or 378 days long. The exact mechanism by which this was done is not clearly specified in ancient sources. Modern scholarship holds that Februarius was...
or Mercedinus), was added from time to time between the two parts of February. This caused the second part of February to be incorporated in the intercalary month as its last five days; there was thus no change either in their dates or the festivals observed on them. The resulting leap year was either 377 or 378 days long, depending on whether Intercalaris began on the day after the Terminalia or the second day after the Terminalia. Intercalaris had 27 days, its nones were on the fifth and its ides on the thirteenth as usual; the next following day was a.d. XV Kal. Mart.
The decision to insert the intercalary month
Intercalation
Intercalation 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 :...
was the responsibility of the pontifex maximus
Pontifex Maximus
The Pontifex Maximus was the high priest of the College of Pontiffs in ancient Rome. This was the most important position in the ancient Roman religion, open only to patricians until 254 BC, when a plebeian first occupied this post...
. On average, this happened roughly in alternate years. The system of aligning the year through intercalary months broke down at least twice: the first time was during and after the Second Punic War. It led to the reform of the Lex Acilia in 191 BC, the details of which are unclear, but it appears to have successfully regulated intercalation
Intercalation
Intercalation 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 :...
for over a century. The second breakdown was in the middle of the 1st century BC and may have been related to the increasingly chaotic and adversarial nature of Roman politics at the time. The position of pontifex maximus was not a full-time job; it was held by a member of the Roman elite, who would almost invariably be involved in the machinations of Roman politics. Because a Roman calendar year defined the term of office of elected Roman magistrates, a pontifex maximus would have reason to lengthen a year in which he or his allies were in power, or shorten a year in which his political opponents held office. It was while Julius Caesar
Julius Caesar
Gaius Julius Caesar was a Roman general and statesman and a distinguished writer of Latin prose. He played a critical role in the gradual transformation of the Roman Republic into the Roman Empire....
was pontifex maximus that the calendar was overhauled, with the result being the Julian calendar
Julian calendar
The Julian calendar began in 45 BC as a reform of the Roman calendar by Julius Caesar. It was chosen after consultation with the astronomer Sosigenes of Alexandria and was probably designed to approximate the tropical year .The Julian calendar has a regular year of 365 days divided into 12 months...
. The calendar reforms were completed during the reign of his successor Augustus
Augustus
Augustus ;23 September 63 BC – 19 August AD 14) is considered the first emperor of the Roman Empire, which he ruled alone from 27 BC until his death in 14 AD.The dates of his rule are contemporary dates; Augustus lived under two calendars, the Roman Republican until 45 BC, and the Julian...
. Quintilis was renamed Iulius (July) in honour of Julius Caesar
Julius Caesar
Gaius Julius Caesar was a Roman general and statesman and a distinguished writer of Latin prose. He played a critical role in the gradual transformation of the Roman Republic into the Roman Empire....
in 44 BC and Sextilis was renamed Augustus (August) in honour of Augustus
Augustus
Augustus ;23 September 63 BC – 19 August AD 14) is considered the first emperor of the Roman Empire, which he ruled alone from 27 BC until his death in 14 AD.The dates of his rule are contemporary dates; Augustus lived under two calendars, the Roman Republican until 45 BC, and the Julian...
in 8 BC.
Months
The three reference dates were probably declared publicly when the lunar conditions were observed. After the reforms of Numa, they occurred on fixed days.- Kalendae (Kalends)—first day of the month, from which the word "calendarCalendarA calendar is a system of organizing days for social, religious, commercial, or administrative purposes. This is done by giving names to periods of time, typically days, weeks, months, and years. The name given to each day is known as a date. Periods in a calendar are usually, though not...
" is derived; it is thought to have originally been the day of the new moonLunar phaseA lunar phase or phase of the moon is the appearance of the illuminated portion of the Moon as seen by an observer, usually on Earth. The lunar phases change cyclically as the Moon orbits the Earth, according to the changing relative positions of the Earth, Moon, and Sun...
. The word derives from καλειν, 'to announce' (the days of the full & new moon for the month). - Nonae (Nones)—thought to have originally been the day of the half moonLunar phaseA lunar phase or phase of the moon is the appearance of the illuminated portion of the Moon as seen by an observer, usually on Earth. The lunar phases change cyclically as the Moon orbits the Earth, according to the changing relative positions of the Earth, Moon, and Sun...
. The Nones fell on the ninth (nonus) day before the Ides (or, by our reckoning, eight days before, i.e. on the 5th or 7th). - Idūs (Ides)—thought to have originally been the day of the full moonLunar phaseA lunar phase or phase of the moon is the appearance of the illuminated portion of the Moon as seen by an observer, usually on Earth. The lunar phases change cyclically as the Moon orbits the Earth, according to the changing relative positions of the Earth, Moon, and Sun...
, corresponds to the 13th of most months, but the 15th of March, May, July, and October.
The day preceding the Kalends, Nones, or Ides was Pridie, e.g. Prid. Id. Mart. = 14 March. Other days were a.d. NN, abbreviation for ante diem NN (meaning "on the Number, numerus of days before the Named reference day, nomen"), e.g. a.d. III Kal. Oct. = on the third day before the October Kalends = 28 September (where this date refers to the early period when September had only 29 days). The inclusive system of counting meant that the second day before the fixed point did not exist (because it was the same as Pridie, and the 'third' day was thus the day before that). Some examples: a.d. IV Non. Jan. = 2 January; a.d. VI Non. Mai. = 2 May; a.d. VIII Id. Apr. = 6 April; a.d. VIII Id. Oct. = 8 October; a.d. XVII Kal. Nov. = 16 October; a.d. XVII Kal. Dec. = 14 November (where the date refers to the early period when November had only 29 days).
Some dates are sometimes known by the name of a festival that occurred on them, or shortly afterwards. Such dates are known for the Feralia
Feralia
Feralia was an ancient Roman public festival celebrating the Manes which fell on the 21st of February as recorded by Ovid in Book II of his Fasti. This day marked the end of Parentalia, a nine day festival honoring the dead ancestors...
, Quirinalia and the Terminalia (though not yet for the Lupercalia
Lupercalia
Lupercalia was a very ancient, possibly pre-Roman pastoral festival, observed on February 13 through 15 to avert evil spirits and purify the city, releasing health and fertility...
). These dates are all after the Ides of February, which suggests that they are connected with resolving an ambiguity that could arise in intercalary years: dates of the form a.d. [N] Kal. Mart. were dates in late February in regular years but were a month later in intercalary years. However, it is much debated whether there was a fixed rule for using festival-based dates. It has been suggested that dates like a.d. X Terminalia (known from an inscription in 94 BC) indicated that the year was intercalary, that it was not intercalary, or that it could be intercalary.
When Julius Caesar
Julius Caesar
Gaius Julius Caesar was a Roman general and statesman and a distinguished writer of Latin prose. He played a critical role in the gradual transformation of the Roman Republic into the Roman Empire....
added a day to September, he added it to the end of the month, so as not to disturb the dates of religious festivals in September, but the effect was to increase the count of the day that immediately followed the Ides:
- a.d. XVIII Kal. Oct. = 18 days before the Kalends of October = 14 September
As a result, the position of all the following dates in September got bumped up by one day. This has some unexpected effects. For example, the emperor Augustus
Augustus
Augustus ;23 September 63 BC – 19 August AD 14) is considered the first emperor of the Roman Empire, which he ruled alone from 27 BC until his death in 14 AD.The dates of his rule are contemporary dates; Augustus lived under two calendars, the Roman Republican until 45 BC, and the Julian...
was born on 23 September 63 BC. In the pre-Julian calendar this is eight days before the Kalends of October (or, in Roman style, a.d. VIII Kal. Oct.), but in the Julian calendar it is nine days (a.d. IX Kal. Oct.). Because of this ambiguity, his birthday was sometimes celebrated on both dates, i.e. (for us) on both 23 and 24 September.
Nundinal cycle
The Romans of the Republic, like the Etruscans, used a "market week" of eight days, marked as A to H in the calendar. A nundina was the market day; etymologically, the word is related to novem, "nine," because the Roman system of counting was inclusive. The market "week" is the nundinal cycle. Since the length of the year was not a multiple of eight days, the letter for the market day (known as a "nundinal letter") changed every year. For example, if the letter for market days in some year was A and the year was 355 days long, then the letter for the next year would be F.The nundinal cycle formed one rhythm of day-to-day Roman life; the market day was the day that country people would come to the city, and the day that city people would buy their eight days' worth of groceries. For this reason, a law was passed in 287 BC (the Lex Hortensia
Lex Hortensia
Lex Hortensia was a law passed in Ancient Rome in 287 BC which made all resolutions passed by plebeians binding on all citizens.-Introduction:...
) that forbade the holding of meetings of the comitia (for example to hold elections) on market days, but permitted the holding of legal actions. In the late republic, a superstition arose that it was unlucky to start the year with a market day (i.e. for the market day to fall on 1 January, with a letter A), and the pontiff
Pontiff
A pontiff was, in Roman antiquity, a member of the principal college of priests . The term "pontiff" was later applied to any high or chief priest and, in ecclesiastical usage, to a bishop and more particularly to the Bishop of Rome, the Pope or "Roman Pontiff".-Etymology:The English term derives...
s, who regulated the calendar, took steps to avoid it.
Because the nundinal cycle was absolutely fixed at eight days under the Republic, information about the dates of market days is one of the most important tools we have for working out the Julian equivalent of a Roman date in the pre-Julian calendar. In the early Empire, the Roman market day was occasionally changed. The details of this are not clear, but one likely explanation is that it would be moved by one day if it fell on the same day as the festival of Regifugium
Regifugium
In the Roman religion, Regifugium or Fugalia was an annual observance that took place every February 24. In Latin, the name of the observance transparently means "flight of the king."...
, an event that could occur every other Julian leap year. When this happened the market day would be moved to the next day, which was the bissextile (leap) day.
The nundinal cycle was eventually replaced by the modern seven-day week
Week
A week is a time unit equal to seven days.The English word week continues an Old English wice, ultimately from a Common Germanic , from a root "turn, move, change"...
, which first came into use in Italy during the early imperial period, after the Julian calendar
Julian calendar
The Julian calendar began in 45 BC as a reform of the Roman calendar by Julius Caesar. It was chosen after consultation with the astronomer Sosigenes of Alexandria and was probably designed to approximate the tropical year .The Julian calendar has a regular year of 365 days divided into 12 months...
had come into effect. The system of nundinal letters was also adapted for the week, see dominical letter
Dominical letter
Dominical letters are letters A, B, C, D, E, F and G assigned to days in a cycle of seven with the letter A always set against 1 January as an aid for finding the day of the week of a given calendar date and in calculating Easter....
. For a while, the week and the nundinal cycle coexisted, but by the time the week was officially adopted by Constantine in AD 321 the nundinal cycle had fallen out of use. For further information on the week, see week
Week
A week is a time unit equal to seven days.The English word week continues an Old English wice, ultimately from a Common Germanic , from a root "turn, move, change"...
and days of the week.
Character of the day
Each day of the Roman calendar was associated with a "character", which was marked in the fastiFasti
In ancient Rome, the fasti were chronological or calendar-based lists, or other diachronic records or plans of official and religiously sanctioned events...
. The most important of these were dies fasti, marked by an F, on which legal matters could normally be heard, dies nefasti, marked by an N, on which they could not, and dies comitiales, marked by a C, on which meetings of the public assemblies known as comitia were permitted, subject to other constraints such as the Lex Hortensia
Lex Hortensia
Lex Hortensia was a law passed in Ancient Rome in 287 BC which made all resolutions passed by plebeians binding on all citizens.-Introduction:...
. A few days had a different character, e.g. EN (endotercissus or perhaps endoitio exitio nefas), a day in which legal actions were permitted on half of the day only, and NP, which were public holidays.
Years
Roman Republic
The Roman Republic was the period of the ancient Roman civilization where the government operated as a republic. It began with the overthrow of the Roman monarchy, traditionally dated around 508 BC, and its replacement by a government headed by two consuls, elected annually by the citizens and...
, the years were not counted. Instead they were named after the consul
Consul
Consul was the highest elected office of the Roman Republic and an appointive office under the Empire. The title was also used in other city states and also revived in modern states, notably in the First French Republic...
s who were in power at the beginning of the year (see List of Republican Roman Consuls). For example, 205 BC was The year of the consulship of Publius Cornelius Scipio Africanus and Publius Licinius Crassus. Lists of consuls were maintained in the fasti
Fasti
In ancient Rome, the fasti were chronological or calendar-based lists, or other diachronic records or plans of official and religiously sanctioned events...
.
However, in the later Republic, historians and scholars began to count years from the founding of the city of Rome. Different scholars used different dates for this event. The date most widely used today is that calculated by Varro
Marcus Terentius Varro
Marcus Terentius Varro was an ancient Roman scholar and writer. He is sometimes called Varro Reatinus to distinguish him from his younger contemporary Varro Atacinus.-Biography:...
, 753 BC, but other systems varied by up to several decades. Dates given by this method are numbered ab urbe condita
Ab urbe condita
Ab urbe condita is Latin for "from the founding of the City ", traditionally set in 753 BC. AUC is a year-numbering system used by some ancient Roman historians to identify particular Roman years...
(meaning from the founding of the city, and abbreviated AUC). When reading ancient works using AUC dates, care must be taken to determine the epoch used by the author before translating the date into a Julian year.
The first day of the consular term, which was effectively the first day of the year, changed several times during Roman history. It became 1 January in 153 BC. Before then it was 15 March. Earlier changes are a little less certain. There is good reason to believe it was 1 May for most of the 3rd century BC, until 222 BC. Livy mentions consulates starting on 1 July before then, and arguments exist for other dates at earlier times.
Converting pre-Julian dates
The fact that we use the same month names as the Romans encourages us to assume that a Roman date occurred on the same Julian date as its modern equivalent. This assumption is not correct. Even early Julian dates, before the leap year cycle was stabilised, are not quite what they appear to be. For example, it is well known that Julius Caesar was assassinated on the Ides of MarchIdes of March
The Ides of March is the name of the 15th day of March in the Roman calendar, probably referring to the day of the full moon. The word Ides comes from the Latin word "Idus" and means "half division" especially in relation to a month. It is a word that was used widely in the Roman calendar...
in 44 BC, and this is usually converted to 15 March 44 BC. While he was indeed assassinated on the 15th day of the Roman month Martius, the equivalent date on the modern Julian calendar is probably 14 March 44 BC.
Finding the exact Julian equivalent of a pre-Julian date can be very hard. Since we have an essentially complete list of the consuls, it is not difficult to find the Julian year that generally corresponds to a pre-Julian year. However, our sources very rarely tell us which years were regular, which were intercalary, and how long an intercalary year was. Nevertheless, we do know that the pre-Julian calendar could be substantially out of alignment with the Julian calendar. Two precise astronomical synchronisms given by Livy show that in 168 BC the two calendars were misaligned by more than two months, and in 190 BC they were four months out of alignment.
We have a number of other clues to help us reconstruct the Julian equivalent of pre-Julian dates. First, we know the precise Julian date for the start of the Julian calendar (although there is some uncertainty even about that), and we have detailed sources for the previous decade or so, mostly in the letters and speeches of Cicero
Cicero
Marcus Tullius Cicero , was a Roman philosopher, statesman, lawyer, political theorist, and Roman constitutionalist. He came from a wealthy municipal family of the equestrian order, and is widely considered one of Rome's greatest orators and prose stylists.He introduced the Romans to the chief...
. Combining these with what we know about how the calendar worked, especially the nundinal cycle, we can accurately convert Roman dates after 58 BC relative to the start of the Julian calendar. Also, the histories of Livy
Livy
Titus Livius — known as Livy in English — was a Roman historian who wrote a monumental history of Rome and the Roman people. Ab Urbe Condita Libri, "Chapters from the Foundation of the City," covering the period from the earliest legends of Rome well before the traditional foundation in 753 BC...
give us exact Roman dates for two eclipses in 190 BC and 168 BC, and we have a few loose synchronisms to dates in other calendars which help to give rough (and sometimes exact) solutions for the intervening period. Before 190 BC the alignment between the Roman and Julian years is determined by clues such as the dates of harvests mentioned in the sources.
Combining these sources of data, we are able to estimate approximate Julian equivalents of Roman dates back to the start of the First Punic War
First Punic War
The First Punic War was the first of three wars fought between Ancient Carthage and the Roman Republic. For 23 years, the two powers struggled for supremacy in the western Mediterranean Sea, primarily on the Mediterranean island of Sicily and its surrounding waters but also to a lesser extent in...
in 264 BC. However, while we have enough data to make such reconstructions, the number of years before 45 BC for which we can convert pre-Julian Roman dates to Julian dates with certainty is very small, and several reconstructions of the pre-Julian calendar are possible. A detailed reconstruction giving conversions from pre-Julian dates into Julian dates is available.
See also
- Ab urbe conditaAb urbe conditaAb urbe condita is Latin for "from the founding of the City ", traditionally set in 753 BC. AUC is a year-numbering system used by some ancient Roman historians to identify particular Roman years...
- Ancient RomeAncient RomeAncient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....
- Gregorian calendarGregorian calendarThe Gregorian calendar, also known as the Western calendar, or Christian calendar, is the internationally accepted civil calendar. It was introduced by Pope Gregory XIII, after whom the calendar was named, by a decree signed on 24 February 1582, a papal bull known by its opening words Inter...
- Julian calendarJulian calendarThe Julian calendar began in 45 BC as a reform of the Roman calendar by Julius Caesar. It was chosen after consultation with the astronomer Sosigenes of Alexandria and was probably designed to approximate the tropical year .The Julian calendar has a regular year of 365 days divided into 12 months...
- Roman festivalsRoman festivalsIn ancient Roman religion, holidays were celebrated to worship and celebrate a certain god or divine event, and consisted of religious observances and festival traditions, usually with a large feast, and often featuring games . The most important festivals were the Saturnalia, the Consualia, the...