Sed ut hos annos omittam caligine iam profundae vetustatis obductos, in his quoque, qui sunt recentioris memoriae et ad cursum lunae vel solis instituti, quanta sit varietas facile est cognoscere, si quis vel in unius Italiae gentibus, ne dicam peregrinis, velit inquirere. nam ut alium Ferentini alium Lavinii itemque Albani vel Romani habuerunt annum, ita et aliae gentes. omnibus tamen fuit propositum suos civiles annos varie intercalandis mensibus ad unum illum verum naturalemque corrigere. de quibus omnibus disserere quoniam longum est, ad Romanorum annum transibimus. Annum vertentem Romae Licinius quidem Macer et postea Fenestella statim ab initio duodecim mensum fuisse scripserunt: sed magis Iunio Gracchano et Fulvio et Varroni et Suetonio aliisque credendum, qui decem mensum putarunt fuisse, ut tunc Albanis erat, unde orti Romani. hi decem menses dies CCCIIII hoc modo habebant: Martius XXXI, Aprilis XXX, Maius XXXI, Iunius XXX, Quintilis XXXI, Sextilis et September tricenos, October XXXI, November et December XXX; quorum quattuor maiores pleni, ceteri sex cavi vocabantur. postea sive a Numa, ut ait Fulvius, sive, ut Iunius, a Tarquinio XII facti sunt menses et dies CCCLV, quamvis luna XII suis mensibus CCCLIIII dies videbatur explere. sed ut dies unus abundaret, aut per inprudentiam accidit, aut, quod magis credo, ea superstitione qua inpar numerus plenus et magis faustus habebatur. certe ad annum priorem unus et quinquaginta dies accesserunt: qui quia menses duo non explerent, sex illis cavis mensibus dies sunt singuli detracti et ad eos additi, factique dies LVII, et ex his duo menses, Ianuarius undetriginta dierum, Februarius duodetriginta. adque ita omnes menses pleni et inpari dierum numero esse coeperunt, excepto Februario, qui solus cavus et ob hoc ceteris infaustior est habitus. denique cum intercalarium mensem viginti duum vel viginti trium dierum alternis annis addi placuisset, ut civilis annus ad naturalem exaequaretur, in mense potissimum Februario inter terminalia et regifugium intercalatum est, idque diu factum prius quam sentiretur annos civiles aliquanto naturalibus esse maiores, quod delictum ut corrigeretur, pontificibus datum negotium eorumque arbitrio intercalandi ratio permissa. sed horum plerique ob odium vel gratiam, quo quis magistratu citius abiret diutiusve fungeretur aut publici redemtor ex anni magnitudine in lucro damnove esset, plus minusve ex libidine intercalando rem sibi ad corrigendum mandatam ultro quod depravarunt, adeo aberratum est ut G. Caesar pontifex maximus suo III et M. Aemilii Lepidi consulatu, quo retro delictum corrigeret, duos menses intercalarios dierum LXVII in mensem Novembrem et Decembrem interponeret, cum iam mense Februario dies III et XX intercalasset, faceretque eum annum dierum CCCCXLV, simul providens in futurum ne iterum erraretur: nam intercalario mense sublato annum civilem ad solis cursum formavit. itaque diebus CCCLV addidit decem, quos per septem menses, qui dies undetricenos habebant, ita discriberet, ut Ianuario et Sextili et Decembri bini accederent, ceteris singuli; eosque dies extremis partibus mensium adposuit, ne scilicet religiones sui cuiusque mensis a loco summoverentur. quapropter nunc cum in septem mensibus dies singuli et triceni sint, quattuor tamen illi ita primitus instituti eo dinoscuntur quod nonas habent septimanas, ceteri tres quintanas. praeterea pro quadrante diei, qui annum verum suppleturus videbatur, instituit ut peracto quadrienni circuitu dies unus, ubi mensis quondam solebat, post terminalia intercalaretur, quod nunc bissextum vocatur. ex hoc anno ita a Iulio Caesare ordinato ceteri ad nostram memoriam Iuliani appellantur, eique consurgunt ex quarto Caesaris consulatu. qui etiam si optimo , non soli tamen ad annum naturae aptati sunt: nam et priores anni, etiam si qui decemmenstres fuerunt, nec Romae modo vel per Italiam, sed et aput gentes omnes, quantum poterat, idem fuerunt correcti. itaque cum de aliquo annorum numero hic dicetur, non alios par erit quam naturales accipere. secundum quam rationem nisi fallor hic annus, cuius velut index et titulus quidam est V. C. Pii et Pontiani consulatus, ab olympiade prima millensimus est et quartus decimus, ex diebus dumtaxat aestivis, quibus agon Olympicus celebratur; a Roma autem condita nongentensimus nonagensimus primus, et quidem ex Parilibus, unde urbis anni numerantur; eorum vero annorum quibus Iulianis nomen est ducentesimus octogensimus tertius, sed ex die Kal. Ianuariarum, unde Iulius Caesar anni a se constituti fecit principium; idcirco aliis a novo sole, id est a bruma, aliis ab aestivo solstitio, plerisque ab aequinoctio verno, partim ab autumnali aequinoctio, quibusdam ab ortu vergiliarum, nonnullis ab earum occasu, multis a canis exortu incipere annus naturalis videtur. Mensium genera duo: nam alii sunt naturales, alii civiles. naturalium species duae, quod partim solis partim lunae esse dicuntur. secundum solem fit mensis, dum sol unum quodque in zodiaco orbe signum percurrit; lunaris est autem temporis quoddam spatium a nova luna. civiles menses sunt numeri quidam dierum quos una quaeque civitas suo instituto observat, ut nunc Romani a kalendis in kalendas. naturales et antiquiores et omnium gentium communes sunt, civiles et posterius instituti et ad unam quamque pertinent civitatem. luna autem singulos suos menses conficit diebus undetriginta circiter et dimidiato, sed et hos inter se dispares, alias longiores, alias breviores. at civitatium menses vel magis numero dierum inter se discrepant, sed dies ubique habent totos. apud Albanos Martius est sex et triginta, Maius viginti duum, Sextilis duodeviginti, September sedecim: Tusculanorum Quintilis dies habet XXXVI, October XXXII, idem October apud Aricinos XXXVIIII. minime videntur errasse qui ad lunae cursum menses civiles adcommodarunt, ut in Graecia plerique, apud quos alterni menses ad tricenos dies sunt facti. maiores quoque nostri idem sunt aemulati, cum annum dierum CCCLV haberent. sed Divus Iulius cum videret hac ratione neque ad lunam menses, ut oportebat, neque annos ad solem convenire, maluit annum corrigere, ut sic etiam menses civiles cum veris illis solaribus, etsi non singuli, tamen universi ad anni finem necessario concurrerent. Nomina decem mensibus antiquis Romulum fecisse Fulvius et Iunius auctores sunt. et quidem duos primos a parentibus suis nominasse, Martium a Marte patre, Aprilem ab Aphrodite, id est Venere, unde maiores eius oriundi dicebantur. proximos duos a populo, Maium a maioribus natu, Iunium a iunioribus. ceteros ab ordine quo singuli erant, Quintilem usque Decembrem perinde a numero. Varro autem Romanos a Latinis nomina mensum accepisse arbitratus auctores eorum antiquiores quam urbem fuisse satis argute docet. itaque Martium mensem a Marte quidem nominatum credit, non quia Romuli fuerit pater, sed quod gens Latina bellicosa. Aprilem autem non ab Aphrodite, sed ab aperiendo, quod tunc ferme cuncta gignantur et nascendi claustra aperiat natura. Maium vero non a maioribus, sed a Maia nomen accepisse, quod eo mense tam Romae quam antea in Latio res divina Maiae fit et Mercurio. Iunium quoque a Iunone potius quam iunioribus, quod illo mense maxime Iunoni honores habentur. Quintilem, quod loco iam apud Latinos fuerit quinto, item Sextilem ac deinceps ad Decembrem a numeris appellatos. ceterum Ianuarium et Februarium postea quidem additos, sed nominibus iam ex Latio sumptis; et Ianuarium ab Iano, cui adtributus est, nomen traxisse, Februarium a februo. est februum quidquid piat purgatque, et februamenta purgamenta, item februare purgare et purum facere. februum autem non idem usquequaque dicitur: nam aliter in aliis sacris februatur, hoc est purgatur. in hoc autem mense Lupercalibus, cum Roma lustratur, salem calidum ferunt, quod februum appellant, unde dies Lupercalium proprie februatus et ab eo porro mensis Februarius vocitatur. ex his duodecim mensibus duorum tantum nomina inmutata. nam Quintilis Iulius cognominatus est C. Caesare V et M. Antonio cons. anno Iuliano secundo: qui autem Sextilis fuerat, ex SC. Marcio Censorino C. Asinio Gallo cons. in Augusti honorem dictus est Augustus anno Augusti vicensimo. quae nomina etiam nunc ad hanc permanent memoriam. postea vero multi principes nomina quaedam mensium inmutaverunt suis nuncupando nominibus; quod aut ipsi postmodum mutaverunt, aut post obitum eorum illa nomina pristina suis reddita mensibus.

But let me pass over these years [of the earliest peoples], already lost in the darkness of the distant past. Even among the years of more recent memory, set by the course of the moon or the sun, it is easy to see how much variety there is. One only has to look at the peoples of Italy alone, to say nothing of foreign ones. The people of Ferentinum had one year, those of Lavinium another, the Albans and the Romans others again, and so did other peoples. But all of them aimed to correct their civil years to match the one true, natural year, by inserting extra months in different ways. It would take too long to discuss all of these, so I will move on to the year of the Romans. Licinius Macer, and later Fenestella, wrote that the year at Rome had twelve months from the very beginning. But we should rather believe Junius Gracchanus, Fulvius, Varro, Suetonius and others, who thought it had ten months. So it was at that time among the Albans, from whom the Romans came. These ten months had 304 days, like this: March 31, April 30, May 31, June 30, Quintilis 31, Sextilis and September 30 each, October 31, and November and December 30. The four longer months were called "full," and the other six "hollow." Later there came to be twelve months and 355 days. Fulvius says that Numa did this, and Junius that Tarquin did. Yet the moon seemed to complete its twelve months in 354 days. The one extra day was either a mistake or, as I rather believe, came from the superstition that held an odd number to be full and luckier. In any case, 51 days were added to the old year. These were not enough to fill two months, so one day was taken from each of the six hollow months and added to them. That made 57 days, and from these came two months, January with 29 days and February with 28. So all the months came to be full, with an odd number of days, except February. It alone was hollow, and so it was thought less lucky than the rest. Next it was decided to add an extra month of 22 or 23 days every other year, so that the civil year would equal the natural one. It was usually inserted in February, between the Terminalia and the Regifugium. This went on for a long time before anyone noticed that the civil years were somewhat longer than the natural ones. To correct this fault, the task was given to the pontiffs, and the method of inserting months was left to their judgment. But most of them, out of hatred or favor, inserted more days or fewer as they pleased. They wanted one official to leave office sooner, or another to serve longer, or a contractor for the public revenues to gain or lose by the length of the year. So they actually spoiled the very thing they had been given to correct. Things went so far wrong that Gaius Caesar, as chief pontiff, set out to correct the past error. In the year when he was consul for the third time, with Marcus Aemilius Lepidus, he put two extra months, of 67 days in all, between November and December. He had already inserted 23 days in February, and so he made that year 445 days long. At the same time he made sure the error would not happen again. He did away with the extra month and shaped the civil year to the course of the sun. So he added ten days to the 355. He shared them out among the seven months that had 29 days: two each went to January, Sextilis and December, and one each to the others. He put these days at the ends of the months, so that the religious festivals of each month would not be moved from their places. So today seven months have 31 days. But the four that had 31 days from the start can still be told apart. Their Nones fall on the seventh day, while the other three have them on the fifth. Then there was the quarter of a day that seemed to be needed to complete the true year. For this he ruled that, at the end of each four-year cycle, one day should be inserted after the Terminalia, where the extra month used to go. This day is now called the bissextum. The years since then, down to our own time, are called Julian after this year that Julius Caesar set in order. They are counted from Caesar's fourth consulship. Even if these are the best [words are lost here], they are not the only years fitted to the year of nature. The earlier years too, even those of ten months, were corrected in the same way as far as possible, not only at Rome or in Italy but among all peoples. So whenever I speak here of a number of years, they should be taken as natural years. By this reckoning [of Varro's], unless I am mistaken, the present year is the 1,014th since the first Olympiad. This year is marked and named, as it were, by the consulship of those most distinguished men, Pius and Pontianus. Its Olympic count starts from the summer days when the Olympic games are held. It is the 991st year since Rome was founded, counting from the Parilia, the festival from which the city's years are counted. Of the years called Julian, it is the 283rd, counting from January 1, the day Julius Caesar made the start of the year he set up. So the natural year seems to some to begin with the new sun, that is, at the winter solstice, and to others at the summer solstice. Most think it begins at the spring equinox, and some at the autumn equinox. Some date it from the rising of the Pleiades, others from their setting, and many from the rising of the Dog Star. There are two kinds of months: some are natural and others civil. The natural months are of two types, for some are said to belong to the sun and some to the moon. A month of the sun is the time the sun takes to pass through one sign of the zodiac. A month of the moon is a span of time from a new moon [to the next]. Civil months are set numbers of days that each city keeps by its own custom, as the Romans now count from one Kalends to the next. The natural months are older and shared by all peoples. The civil ones were set up later, and each belongs to a single city. The moon completes each of its months in about 29 and a half days, but these too differ, some longer and some shorter. The months of cities differ from one another even more in their number of days, but everywhere they are made of whole days. Among the Albans, March has 36 days, May 22, Sextilis 18 and September 16. At Tusculum, Quintilis has 36 days and October 32, and at Aricia October has 39. Those who fitted their civil months to the course of the moon seem to have gone least wrong. Most cities in Greece did this, and there every other month was made 30 days long. Our ancestors copied them when they had a year of 355 days. But the Deified Julius saw that under this system the months did not match the moon, as they should, and the years did not match the sun. He chose to correct the year. In this way the civil months would match the true months of the sun, if not one by one, then necessarily all together by the end of the year. Fulvius and Junius report that Romulus named the ten ancient months. He named the first two after his parents: March (Martius) after his father, Mars, and April (Aprilis) after Aphrodite, that is, Venus, from whom his ancestors were said to descend. He named the next two after the people: May (Maius) after the elders (maiores), and June (Iunius) after the younger men (iuniores). The rest, from Quintilis to December, he named by their place in order, by number. But Varro held that the Romans took the names of the months from the Latins. He shows quite cleverly that those who made the names were older than the city. So he believes that March was indeed named after Mars, but not because Mars was the father of Romulus. It was because the Latin people were warlike. April, he thinks, came not from Aphrodite but from "opening" (aperire), because almost everything is born then, and nature opens the gates of birth. May, he says, took its name not from the elders but from Maia, because in this month sacrifice is made to Maia and Mercury, now at Rome as before in Latium. June too came from Juno rather than from the younger men, because in that month Juno is honored most of all. Quintilis was so called because it was already fifth in place among the Latins, and likewise Sextilis and the rest up to December were named from numbers. January and February, he says, were indeed added later, but with names already taken from Latium. January took its name from Janus, to whom it is assigned, and February from februum. Februum is anything that cleanses and purifies, and februamenta are purifications. Likewise februare means to purify and make clean. But februum does not mean the same thing everywhere, because purifying is done in different ways in different rites. In this month, at the Lupercalia, when Rome is purified, they carry hot salt, which they call februum. So the day of the Lupercalia is properly called februatus, and from it in turn the month is called February. Of these twelve months, only two have had their names changed. Quintilis was renamed Iulius [July] when Gaius Caesar, for the fifth time, and Mark Antony were consuls, in the second Julian year. The month that had been Sextilis was renamed Augustus in honor of Augustus by a decree of the senate. That was when Marcius Censorinus and Gaius Asinius Gallus were consuls, in the twentieth year of Augustus. These names have lasted to our own day. Later, many emperors changed the names of some months, calling them by their own names. But either they changed them back themselves later, or after their deaths the old names were given back to the months.