Varro (1st century BC) uses the name in his agricultural treatise, in a passage of dialogue in which the interlocutors explain that some farming tasks should be done when the moon is waxing, while the waning phase facilitates others, such as harvesting, shearing sheep, and clearing woodlands. It seems to be a name used by country people. Orosius (5th century AD) has a form Ianium (in some readings) equivalent to Dianium, referring to either a shrine or the Temple of Diana on the Aventine Hill. Diana is one of the Roman goddesses most often identified with the moon, but Usener thought Iana might be better identified with Juno Lucina.
The Church Father Tertullian, however, calls Iana a diva arquis, "goddess of arches" (Latin arcus or arquus, "arch; rainbow"). The arch as a passageway or portal suggests Iana as the female counterpart of Janus, whose role as a "doorkeeper" includes functions pertaining to time and the heavens. Varro's contemporary Nigidius Figulus identified Janus with Apollo and Iana with Diana.
- Varro, De re rustica 1.37.1���3; Arthur Bernard Cook, Zeus, vol. 2, pt. 1, p. 339.
- Orosius, Histories 5.12.6; Cook, Zeus, p. 339.
- The Dianium was located at the intersection of the Vicus Cuprius and the Clivus Orbius (or Urbius) on the Oppian Hill, according to Livy 1.48.6. It had disappeared by the time of Livy, but was still referenced as a landmark; Lawrence Richardson, A New Topographical Dictionary of Ancient Rome (Johns Hopkins University Press, 1992), p. 109.
- Richardson, Topographical Dictionary, p. 109.
- Hermann Usener, "Zwillingsbildung," as reprinted in Kleine Schriften (Teubner, 1904), vol. 4, p. 340.
- Tertullian, Ad nationes 2.15.
- Stefan Weinstock, "Martianus Capella and the Cosmic System of the Etruscans," Journal of Roman Studies 36 (1946), p. 106; René Guénon, Fundamental Symbols (Cambridge: Quinta Essentia, 1995), chapter 37, "The Solstitial Gate."
- As preserved by Macrobius, Saturnalia 1.9.8; Cook, Zeus, p. 339.
- W.H. Roscher, Ausführliches Lexikon der griechischen und römischen Mythologie (Leipzig: Teubner, 1890–94), vol. 2, pt. 1, p. 199.