Brumalia (Latin: Brumalia, [bruːˈmaːlɪ.a], "winter festivals") was an ancient Roman, winter solstice festival honoring Saturn/Cronus and Ceres/Demeter, and Bacchus in some cases. By the Byzantine era, celebrations commenced on 24 November and lasted for a month, until Saturnalia and the "Waxing of the Light". The festival included night-time feasting, drinking, and merriment. During this time, prophetic indications were taken as prospects for the remainder of the winter. The festival was celebrated as late as the 6th century, until emperor Justinian's repression of paganism.
The festival marked a break for the Senate and included feasting and general merry making as well as divination to determine the city's prospects for the coming year. It also incorporated a number of smaller holidays associated with various Gods. Some modern Pagans use the word Brumalia to simply indicate the winter holiday season including all of its various festivals and activities. This seems quite in keeping with the spirit of the ancient use of the word.
John Malalas in his Chronicle 7.7 gives an account of the origins of the festival. This tells us it was in the winter, and instituted by Romulus (or “Romus” as Malalas calls him).
Because of this Romus devised what is known as the Brumalia, declaring, it is said, that the emperor of the time must entertain his entire senate and officials and all who serve in the palace, since they are persons of consequence, during the winter when there is a respite from righting. He began by inviting and entertaining first those whose names began with alpha, and so on, right to the last letter; he ordered his senate to entertain in the same way. They too entertained the whole army, and those they wanted. . . . This custom of the Brumalia has persisted in the Roman state to the present day. — [The Chronicle of John Malalas, trans. E. Jeffreys et al. (Byzantina Australiensia 4, Melbourne, 1986), p. 95]