Question: In ancient Roman religion, Fontus or Fons (plural "Fontes", "Font" or "Source") was a god of wells and springs, a religious festival called the Fontinalia was held on October 13 in his honor, festivals in ancient Rome were an important part of Roman religious life during which eras, and one of the primary features of the Roman calendar?

<P0-S0>  A religious festival called the Fontinalia was held on October 13 in his honor. <P0-S1>  Throughout the city, fountains and wellheads were adorned with garlands. <P0-S2> In ancient Roman religion, Fontus or Fons (plural "Fontes", "Font" or "Source") was a god of wells and springs. <SEP> <P1-S0> The Fasti (Latin: "Fastorum Libri Sex" , "Six Books of the Calendar"), sometimes translated as The Book of Days or On the Roman Calendar, is a six-book Latin poem written by the Roman poet Ovid and published in 8 AD. <P1-S1>  Ovid is believed to have left the "Fasti" incomplete when he was exiled to Tomis by the emperor Augustus in 8 AD. <P1-S2>  Written in elegiac couplets and drawing on conventions of Greek and Latin didactic poetry, the "Fasti" is structured as a series of eye-witness reports and interviews by the first-person "vates" ("poet-prophet" or "bard") with Roman deities, who explain the origins of Roman holidays and associated customs—often with multiple aetiologies. <P1-S3>  The poem is a significant, and in some cases unique, source of fact in studies of religion in ancient Rome; and the influential anthropologist and ritualist J.G. Frazer translated and annotated the work for the Loeb Classical Library series. <P1-S4>  Each book covers one month, January through June, of the Roman calendar, and was written several years after Julius Caesar replaced the old system of Roman time-keeping with what would come to be known as the Julian calendar. <SEP> <P2-S0> Festivals in ancient Rome were an important part of Roman religious life during both the Republican and Imperial eras, and one of the primary features of the Roman calendar. <P2-S1>  Feriae ("holidays" in the sense of "holy days"; singular also "feriae" or dies ferialis) were either public "(publicae)" or private "(privatae)". <P2-S2>  State holidays were celebrated by the Roman people and received public funding. <P2-S3>  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. <P2-S4>  Although "feriae" were paid for by the state, "ludi" were often funded by wealthy individuals. <P2-S5>  "Feriae privatae" were holidays celebrated in honor of private individuals or by families. <P2-S6>  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 <SEP> <P3-S0> In the myth and religion of ancient Rome, Juturna was a goddess of fountains, wells and springs, and the mother of Fontus by Janus. <P3-S1>  Jupiter turned her into a water nymph – a Naiad – and gave her a sacred well in Lavinium, Latium, as well as another one near the temple to Vesta in the Forum Romanum. <P3-S2>  The pool next to the second well was called Lacus Juturnae. <P3-S3>  A local water nymph or river-god generally presides over a single body of water, but Juturna has broader powers which probably reflect her original importance in Latium, where she had temples in Rome and Lavinium, a cult of healthful waters at Ardea, and the fountain/well next to the lake in the Roman forum. <P3-S4>  It was here in Roman legend that the deities Castor and Pollux watered their horses after bringing news of the Roman victory at the Battle of Lake Regillus in 496 BC (Valerius Maximus, I.8.1; Plutarch, Life of Aemilius Paulus, 25.2, Life of Coriolanus, 3.4).