Festivals in ancient Rome were a very important part of Roman religious life during both the Republican and Imperial eras, and one of the primary features of the Roman calendar. Feriae ("holidays" in the sense of "holy days"; singular also feriae or dies ferialis) were either public (publicae) or private (privatae). State holidays were celebrated by the Roman people and received public funding. Games (ludi), such as the Ludi Apollinares, were not technically feriae, but the days on which they were celebrated were dies festi, holidays in the modern sense of days off work. Although feriae were paid for by the state, ludi were often funded by wealthy individuals. Feriae privatae were holidays celebrated in honor of private individuals or by families.H.H. Scullard, Festivals and Ceremonies of the Roman Republic (Cornell University Press, 1981), pp. 38–39. This article deals only with public holidays, including rites celebrated by the state priests of Rome at temples, as well as celebrations by neighborhoods, families, and friends held simultaneously throughout Rome.

Feriae publicae were of three kinds: Stativae were annual holidays that held a fixed or stable date on the calendar. Conceptivae were annual holidays that were moveable feasts (like Easter on the Christian calendar, or Thanksgiving in North America); the date was announced by the magistrates or priests who were responsible for them. Imperativae were holidays held "on demand" (from the verb impero, imperare, "to order, command") when special celebrations or expiations were called for.Scullard, Festivals and Ceremonies of the Roman Republic, p. 39.

One of the most important sources for Roman holidays is Ovid's Fasti, an incomplete poem that describes and provides origins for festivals from January to June at the time of Augustus.

Keeping the feriae

Varro defined feriae as "days instituted for the sake of the gods."Varro, De lingua latina 6.12 (dies deorum causa instituti, as cited by Scullard, p. 39, noting also the phrase dis dedicati, "dedicated to the gods," in Macrobius, Saturnalia 1.16.2. Religious rites were performed on the feriae, and public business was suspended. Even slaves were supposed to be given some form of rest. Cicero says specifically that people who were free should not engage in lawsuits and quarrels, and slaves should get a break from their labours.Cicero, De legibus 2.29, as cited by Scullard, p. 39. Agricultural writers recognized that some jobs on a farm might still need to be performed, and specified what these were. Some agricultural tasks not otherwise permitted could be carried out if an expiation were made in advance (piaculum), usually the sacrifice of a puppy.Cato the Elder, De agricultura 138; Columella 2.21.2; Scullard, Festivals and Ceremonies of the Roman Republic, p. 39. Within the city of Rome, the flamens and the priest known as the Rex sacrorum were not allowed even to see work done.

On a practical level, those who "inadvertently" worked could pay a fine or offer up a piaculum, usually a pig. Work considered vital either to the gods or preserving human life was excusable, according to some experts on religious law. Although Romans were required not to work, they were not required to take any religious action unless they were priests or had family rites (sacra gentilicia) to maintain.Scullard, Festivals and Ceremonies of the Roman Republic, pp. 39–40.

List of festivals by month Following is a month-by-month list of Roman festivals and games that had a fixed place on the calendar. For some, the date on which they were first established is recorded. A deity's festival often marks the anniversary (dies natalis, "birthday") of the founding of a temple, or a rededication after a major renovation. Festivals not named for deities are thought to be among the oldest on the calendar.Hendrik Wagenvoort, "Initia Cereris," in Studies in Roman Literature, Culture and Religion (Brill, 1956), pp. 163–164.

Some religious observances were monthly. The first day of the month was the Kalends (or Calends, from which the English word "calendar" derives). Each Kalends was sacred to Juno, and the Regina sacrorum ("Queen of the Rites," a public priestess) marked the day by presiding over a sacrifice to the goddess.Emily A. Hemelrijk, "Women and Sacrifice in the Roman Empire," in Ritual Dynamics and Religious Change in the Roman Empire. Proceedings of the Eighth Workshop of the International Network Impact of Empire (Heidelberg, July 5–7, 2007) (Brill, 2009), pp. 258–259, citing Macrobius, Saturnalia 1.15.19. Originally a pontiff and the Rex sacrorum reported the sighting of the new moon, and the pontiff announced whether the Nones occurred on the 5th or 7th of that month. On the Nones, announcements were made regarding events to take place that month; with the exception of the Poplifugia, no major festivals were held before the Nones, though other ceremonies, such as anniversaries of temple dedications, might be carried out. The Ides (usually the 13th, or in a few months the 15th) were sacred to Jupiter. On each Ides, a white lamb was led along the Via Sacra to the Capitolium for sacrifice to Jupiter.

The list also includes other notable public religious events such as sacrifices and processions that were observed annually but are neither feriae nor dies natales. Unless otherwise noted, the calendar is that of H.H. Scullard, Festivals and Ceremonies of the Roman Republic.

Ianuarius 1 (Calends): From 153 BC onward, consuls entered office on this date, accompanied by vota publica (public vows for the wellbeing of the republic and later of the emperor) and the taking of auspices. Festivals were also held for the imported cult of Aesculapius and for the obscure god Vediovis.Scullard, Festivals and Ceremonies of the Roman Republic, pp. 52–58. 3-5: most common dates for Compitalia, a movable feast (feriae conceptivae) 5 (Nones): Dies natalis (founding day) of the shrine of Vica Pota on the Velian HillRecorded only in the Fasti Antiates. 9: Agonalia in honor of Janus, after whom the month January is named; first of at least four festivals named Agonalia throughout the year 11 and 15: Carmentalia, with Juturna celebrated also on the 11th 13 (Ides) 24–26: most common dates for the Sementivae, a feriae conceptivae of sowing, perhaps also known as the Paganalia as celebrated by the pagi 27: Dies natalis of the Temple of Castor and Pollux, or perhaps marking its rededication (see also July 15); Ludi Castorum ("Games of the Castors") celebrated at Ostia during the Imperial period

Februarius In the archaic Roman calendar, February was the last month of the year. The name derives from februa, "the means of purification, expiatory offerings." It marked a turn of season, with February 5 the official first day of spring bringing the renewal of agricultural activities after winter.Scullard, Festivals and Ceremonies of the Roman Republic, pp. 70–71. 1 (Kalends): Dies natalis for the Temple of Juno Sospita, Mother and Queen; sacra at the Grove of Alernus, near the Tiber at the foot of the Palatine Hill 5: Dies natalis for the Temple of Concord on the Capitoline Hill 13 (Ides): minor festival of Faunus on the Tiber Island 13–22: Parentalia, a commemoration of ancestors and the dead among families 13: Parentatio, with appeasement of the Manes beginning at the 6th hour and ceremonies performed by the chief Vestal; temples were closed, no fires burned on altars, marriages were forbidden, magistrates took off their insignia, until the 21st 15: Lupercalia 17: last day of the feriae conceptivae Fornacalia, the Oven Festival; Quirinalia, in honour of Quirinus 21: Feralia, the only public observation of the Parentalia, marked F (dies festus) in some calendars and FP (a designation of uncertain meaning) in others, with dark rites aimed at the gods below (di inferi) 22: Caristia (or Cara Cognatio, "Dear Kindred"), a potluck meal provided by all the family, and shared in a spirit of love and forgiveness 23: Terminalia, in honour of Terminus 24: Regifugium 27: Equirria, first of two horse-racing festivals to Mars

Martius In the old Roman calendar (until perhaps as late as 153 BC), the mensis Martius ("Mars' Month") was the first month of the year. It is one of the few months to be named for a god, Mars, whose festivals dominate the month. 1 (Kalends): the original New Year's Day when the sacred fire of Rome was renewed; the dancing armed priesthood of the Salii celebrated the Feriae Marti (holiday for Mars), which was also the dies natalis ("birthday") of Mars; also the Matronalia, in honor of Juno Lucina, Mars' mother 7: a second festival for Vediovis 9: a dies religiosus when the Salii carried the sacred shields (ancilia) around the city again 14: the second Equirria, a Feriae Marti also called the Mamuralia or sacrum Mamurio 15 (Ides): Feriae Iovi, sacred to Jove, and also the feast of the year goddess Anna Perenna 16–17: the procession of the Argei 17: Liberalia, in honour of Liber; also an Agonalia for Mars 19: Quinquatrus, later expanded into a five-day holiday as Quinquatria, a Feriae Marti, but also a feast day for Minerva, possibly because her temple on the Aventine Hill was dedicated on this day 23: Tubilustrium, purification of the trumpets. 24: a day marked QRCF, when the Comitia Calata met to sanction wills 25: Hilaria, A two-weeks long festival commemorating Cybele's lamentation (fasting, castigation, taurobolium, festoonment, washing) of the death and rejoicing of at the resurrection of her mortal lover Attis. 31: anniversary of the Temple of Luna on the Aventine

Aprilis

A major feriae conceptivae in April was the Latin Festival. 1 (Kalends): Veneralia in honour of Venus 4–10: Ludi Megalenses or Megalesia, in honor of the Magna Mater or Cybele, whose temple was dedicated April 10, 191 BC 5: anniversary of the Temple of Fortuna Publica 12–19: Cerialia or Ludi Cereri, festival and games for Ceres, established by 202 BC 13 (Ides): anniversary of the Temple of Jupiter Victor 15: Fordicidia, offering of a pregnant cow to Tellus ("Earth"), Juppiter Victor (Jupiter The Victorious) 21: Parilia, rustic festival in honour of Pales, and the dies natalis of Rome 21: Dies Romana, a festival linked to the foundation of Rome.Plutarch, Parallel Lives - Life of Romulus, 12.2 (from LacusCurtius) According to legend, Romulus is said to have founded the city of Rome on April 21, 753 BC. From this date, the Roman chronology derived its system, known by the Latin phrase Ab Urbe condita, meaning "from the founding of the City", which counted the years from this presumed foundation. 23: the first of two wine festivals (Vinalia), the Vinalia Priora for the previous year's wine, held originally for Jupiter and later Venus 25: Robigalia, an agricultural festival involving dog sacrifice 27 (28 in the Julian calendar) to May 1: Ludi Florales in honour of Flora, extended to May 3 under the Empire

Maius The feriae conceptivae of this month was the Ambarvalia. 1 (Kalends): Games of Flora continue; sacrifice to Maia; anniversary of the Temple of Bona Dea on the Aventine; rites for the Lares Praestites, tutelaries of the city of Rome 3: in the Imperial period, a last celebration for Flora, or the anniversary of one of her temples 9, 11, 13: Lemuria, a festival of the dead with both public and household rites, possibly with a sacrifice to Mania on the 11th 14: anniversary of the Temple of Mars Invictus (Mars the Unconquered); a second procession of the ArgeiAlternatively dated to May 15. 15 (Ides): Mercuralia, in honor of Mercury; Feriae of Jove 21: one of four Agonalia, probably a third festival for Vediovis 23: a second Tubilustrium; Feriae for Volcanus (Vulcan) 24: QRCF, following Tubilustrium as in March 25: anniversary of the Temple of Fortuna Primigenia

Iunius