The nones is the fifth or seventh of the month in the Roman Calendar. When Roman Antiqua followed a lunar calendar, the nones occurred when the waxing moon had reached its first quarter. However, after the calendar of Roma Antiqua had undergone numerous alterations over the years, the nones were shifted to occur on the fifth or seventh of each month, always falling 9 days prior to the Ides.
The Nones fall on the fifth in the months of January, February, April, June, August, September, November, and December.
The Nones fall on the seventh in the months of March, May, July, and October.
History of the Ritual
On this day in Roma Antiqua, the Rex Sacrorum announced all of the festivals that would be held for the next several weeks leading up into the Kalends of the following month. This announcement was made from the Arx.
There is no permanent patron deity of the Nones, however in some months there are particular deities that are associated with festivities on the Nones.
In the Roman home, the Lares of the familia were especially honored on this day.
vindicat Ausonias Iunonis cura Kalendas;
Idibus alba Iovi grandior agna cadit;
Nonarum tutela deo caret. omnibus istis
(ne fallare cave) proximus ater erit.
omen ab eventu est: illis nam Roma diebus
damna sub averso tristia Marte tulit.
haec mihi dicta semel, totis haerentia fastis,
ne seriem rerum scindere cogar, erunt. 
The worship of Juno claims our Italy’s Kalends,
While a larger white ewe-lamb falls to Jupiter on the Ides:
The Nones though lack a tutelary god. After all these days,
(Beware of any error!), the next day will be ill-omened.
The ill-omen derives from past events: since on those days
Rome suffered heavy losses in military defeat.
Let these words above be applied to the whole calendar,
So I’ll not be forced to break my thread of narrative. 
- ↑ Ovid Fasti, c. 1 ln. 55 - 62 
- ↑ Ovid Fasti Book 1, A. S. Kline trans. http://www.tkline.freeserve.co.uk/OvidFastiBkOne.htm