|The Ptolemaic System|
From Greek Astronomy by Sir Thomas L. Heath.
Our modern calendar is closely based on that implemented by Julius Caesar during 46-45BC, and amended by Pope Gregory XIII in 1582AD.
The ancient Roman calendar was closely linked to the science of astrology, and the teachings of Claudius Ptolemaeus, which were prevalent throughout the entire lifetime of Imperial Rome. Ptolemy's teachings were based, in turn, on those of Plato and Pythagoras who both expounded a geocentric, 'earth-centred' view of the universe in which the sun, moon and planets all revolved about a stationary Earth, positioned as it should be, at the very hub of the cosmos.
Among the lessons published in Ptolemy's astronomical thesis Syntaxis were; "The earth does not change its position in any way whatever", also "Arguments against the earth's rotation". These theories are now known to be infactual but they were not refuted until 1543AD when the Polish astronomer Mikolaj Kopernik (a.k.a. Nicolaus Copernicus 1473-1543) published his heretical work which expounded a heliocentric or 'sun-centred' 'solar-system'. God bless Him!
Like us, the Romans divided each day into 24 hours, and they assigned 12 to the daytime and 12 to the night. These did not run from midnight to midnight as our modern method of timekeeping does, but from sunrise to sunrise. This effectively means that the length of the Roman hour varied according to the season, so that during the summer solstice¹ around June 21st when the period of daylight is considerably longer than the night, the twelve hours assigned to the daytime would each have to be 1 hour and 16 minutes long, while conversely, during the short days of the winter solstice around December 21st, each daylight hour would be only 44 minutes long.
There were only two days during the entire year when the Roman day contained hours of exactly 60 minutes. These dates occurred during the equinoxes,² when the length of the day is exactly equal to that of the night; the vernal equinox occurred every year around March 21st, and the autumnal equinox about September 21st.
This fluid method of timekeeping was perfectly natural to your average Roman, who was not governed by the same rigid schedules prevalent in our modern technological society and did not carry either a wristwatch or a FiloFax.
|Table adapted from Daily Life in Ancient Rome by Jerome Carcopino pp.167-8.|
It should be noted that the times of rising and setting of the Sun also varies with geographical latitude, and the data in the above table shows the length of the daylight hours at the latitude of Rome itself; this table would not be valid for many other cities in the Roman world.
Macrobius tells us that at first, the Romans used the ancient Etruscan Market Week, which consisted of seven working days followed by a market day called the Nunindae. During this eighth day many public auctions were held, and Varro joked that the rural population shaved and came into the city, thus the Nunindae became a day of festivity.
"The custom, however, of referring the days to the seven stars called planets was instituted by the Egyptians, but is now found among all mankind, though its adoption has been comparatively recent; at any rate the ancient Greeks never understood it, so far as I am aware." (Cassius Dio, History of Rome, XXXVII, 18.1)
The astrological or planetary week of seven days is thought to have started in Persian theology, and by the end of the first century AD was in common usage throughout the whole Mediterranean world. Although the planetary week was recognised by the emperor Augustus, he continued to run the ancient market calendar alongside, and it was not until 321AD during the rule of emperor Constantine that the astrological week became fully established in Roman law.
|dies Saturni||'the day of Saturn'||Saturday||Directly from Latin.|
|dies Solis||'Sun day'||Sunday||Likewise.|
|dies Lunae||'Moon day'||Monday||Ditto.|
|dies Martis||'the day of Mars'||Tuesday||OE Tiwesdaeg 'The day of Tiw',|
from Norse Tysdagr.
from Norse Odinsdagr.¹
|dies Iovis||'the day of Jupiter'||Thursday||OE Thursdaeg 'the day of Thor',|
from Norse Thorsdagr.²
|dies Veneris||'the day of Venus'||Friday||OE Frigesdaeg 'the day of Freya',|
from Norse Freyjasdagr.³
A short digression into Norse mythology
The last four days of the week are named in English after Viking gods, and it behooves our purpose to here present a short summation of the four gods from the Norse pantheon after which our modern day names have been derived.
Like the rest of the ancient Mediterranean world, the Romans believed that each day of the week was ruled by a specific god, in particular, the seven gods after whom the sun, moon and planets were named. These celestial-bodies were known to lie at varying distances from the Earth, and listed in order of descending remoteness they were; Saturn, Jupiter, Mars, the Sun, Venus, Mercury and finally, the Moon. If this is the case, why then, are the Roman days of the week not listed in this order? The answer lies in the fact that these seven Roman deities ruled not only over each day of the week, but also over each hour of the day; The Roman historian Cassius Dio explains:
"1 If you begin at the first hour to count the hours of the day and of the night, assigning the first to Kronos¹ [Saturn], the next to the great god [Zeus/Jupiter], the third to Ares [Mars], the fourth to Helios [the Sun], the fifth to Aphrodite [Venus], the sixth to Hermes [Mercury], and the seventh to Selene [the Moon], 2 according to the order of cycles which the Egyptians observe,² and if you repeat the process, covering thus the whole twenty-four hours, you will find that the first hour of the following day comes to the Sun. 3 And if you carry on the operation throughout the next twenty-four hours in the same manner as with the others, you will dedicate the first hour of the third day to the Moon, and if you proceed similarly throughout the rest, each day will receive its appropriate god. This, then, is the tradition." (Cassius Dio, History of Rome, XXXVII, 19.1-3)
Every Roman month contained three days of particular importance;
All other dates were calculated by counting backwards inclusively from these established days, thus March 22nd is '10 days before the Calends of May', October 10th becomes '6 days before the Ides of October' and January 2nd, '4 days before the Nones of January'.
It is known that the Babylonians utilized a calendar of 12 months each containing 30 days, thus they had a year of 360 days. The Romans, prior to the reformation of Caesar, used a system of months of irregular length giving a 355 day civil year, into which an extra month of 22 or 23 days was intercalated every other year. On the 1st January 45BC, after tacking 90 days onto the end of 46BC in order to bring the seasons back into line, Caesar introduced his Julian Calendar, which did not so much reform the ancient Roman calendar but abandon it, instituting instead the familiar solar calendar of 365¼ days. The ten extra days required to bring the Roman year into line with the solar year were divided up and added to the end of several separate months so as not to interfere too much with the existing festival schedule. In addition, an extra day was intercalated every four years in February. Cassius Dio again elucidates:
"1 ... he (Caesar) also established in their present fashion the days of the year, which had got somewhat out of order, since they still at that time measured their months by the moon's revolutions: he did this by adding sixty-seven days, the number necessary to bring the year out even. 2 Some, indeed, have declared that even more were intercalated, but the truth is as I have stated it.¹ He got this improvement from his stay in Alexandria, save in so far as the people there reckon their months as of thirty days each, and afterwards add the five days to the year as a whole, whereas Caesar distributed among seven months these five along with two other days that he took away from one month.² 3 The one day, however, which results from the fourths he introduced into every fourth year, so as to make the annual seasons no longer differ at all except in the slightest degree; at any rate in fourteen hundred and sixty-one years there is need of only one intercalary day.³" (Cassius Dio, History of Rome, XLIII, 26.1-3)
Caesar's intercalary day was not inserted at the end of the month as happens in modern times, but was placed instead between the 24th and 25th of February. Following Caesar's death the pontifices erroneously performed the intercalation every three years, and this mistake had to be rectified by another slight reform implemented by his nephew and successor Augustus Caesar.
|Number of Days in Month|
|Mensis (Month)||Origin of Name||Ante Caesarem||Post Caesarem|
|Januarius (January)||God Janus||29||31|
|Februarius (February)||Februa festivals ¹||28||28|
|Martius (March)||God Mars||31||31|
|Aprilis (April)||Aprilis ²||29||30|
|Maius (May)||Goddess Maia||31||31|
|Junius (June)||Goddess Juno||29||30|
|Julius (July)||Julius Caesar ³||31||31|
|Augustus (August)||Augustus Caesar||29||31|
|September||'The Seventh Month'||29||30|
|October||'The Eighth Month'||31||31|
|November||'The Ninth Month'||29||30|
|December||'The Tenth Month'||29||31|
Caligula renamed September 'Germanicus' after his father in 37AD, but this was overturned following his assassination and the subsequent condemnation of his memory by the senate in 42AD. September was once more renamed 'Germanicus' in 89AD, this time by the Emperor Domitian following his triumph over the Germanic Chatti tribe; he also renamed October 'Domitianus' as this was the month in which he was born. Domitian was also assassinated, his name condemned, and his acts overturned in 96AD.
The post of Consule Ordinaris was an enormously important political office endowed with the greatest legislative, judicial and military authority in the Roman Republic. The office was dual, elective, and of one-year's duration, all aspirants for the position must first have served as praetor, and the two candidates who polled the most votes took up office on the first of January.
There were two divisions in the office of consul; the consules ordinarii, who were the two men who polled the most votes in the yearly consular elections, and the consules suffecti who would sometimes be appointed in republican times to replace a consul who had been killed in battle, or otherwise relieved of his office; often the next-highest polling consular candidate. The duties of 'ordinary' and 'suffect' consul were exactly the same - i.e. to ensure the smooth-running of the Roman state - but there was one important difference; the Roman year was named after the Consules Ordinarii. As one can imagine, the office of 'Ordinary Consul' was extremely sought-after, as its aquisition would forever immortalise the recipient's name in the annals of Rome.
The full list of Roman consuls is available to modern historians, dating from the foundation of the Roman republic in 509 BC, until the division of the empire in 337AD, thanks mainly to classical historians such as Varro and Cassius Dio, who each gave lists of consulars in their works, and to the diligent works of modern historians such as A. Degrassi and T.R.S. Broughton.
Unlike our modern Christian calendar which enumerates the years from the birth of Jesus Christ, the Roman calendar counted the years ab urbe condita or "from the founding of the city". The city of Rome was founded in 753 BC, so this would bracket our list of consuls between a.u.c. 245 and 1090.
"Claudius was born ... on the Kalends of August in the consulship of Iullus Antonius and Fabius Africanus, ..." (Suetonius Claudius II.i)
The above extract from Suetonius' Life of Claudius tells us not only the day Claudius was born - the first of August - but we can also find his year of birth by reference to the list of known consulars, where we find that Fabius Africanus Maximus (the son of Quintus) and Iullus Antonius (the son of Marcus Antonius) were consules ordinarii a.u.c.744; that's 10BC to us mortal folk!
The Julian calendar remained unchanged until the time of pope Gregory the Thirteenth, who in 1582 introduced an emendation which stated that the intercalation should be performed at the turn of each century only if the century was exactly divisible by 400. This amendment was required because the tropical year, as explained above (vide supra), is not exactly 365¼ days long.
The last date in the Julian calendar was Thursday 4th October 1582. This date was followed by the first day in the Gregorian calendar, which was Friday 15th October 1582. The 10 dates in-between (i.e. 5th to 14th October inclusive) were removed from the calendar.
When the Gregorian Calendar was first implemented it was to cause uproar throughout the Roman-Catholic world because it required the deduction of ten days in order to bring the calendar back into line with the seasons, and many uneducated people rioted in the streets thinking that these days had somehow been deducted from their lifespans.
The Gregorian calendar is now used throughout almost the entire modern world, the most famous exceptions being the Greek and Russian Orthodox Churches, who still observe the old Julian calendar.
On this page - indeed throughout the whole of RBO - the acronyms BC (Before Christ) and AD (Anno Domini) are used to denote absolute dates. Please note that I am aware that the use of BCE (Before Common Era) and CE (Common Era) is more 'politically correct' than the BC/AD notation which may cause offence to non-Christians. I simply do not agree with wishy-washy liberals who insist that nursery-rhymes containing the word 'black' be banned, and who condem perfectly good words such as 'chairman' or 'manhole-cover' for their sexual inequality. Sack the lot of them, I say!
Ahem! Off the political soap-box... The primary reference works consulted for this page were; Chronology of the Ancient World by E.J. Bickerman, Greek Astronomy by Sir Thomas L. Heath, Daily Life in Ancient Rome by Jerome Carcopino, The History of Rome by Cassius Dio, translated from Greek by E. Carey, The Collins Gem Latin Dictionary, The Collins English Dictionary and Kennedy's Revised Latin Primer.