Ianuarius

Ianuarius and Februarius were supposed to have been added by Numa Pompilius, the second king of Rome, originally at the end of the year.

[1] Ianuarius is conventionally thought to have taken its name from Janus, the dual-faced god of beginnings, openings, passages, gates and doorways,[1] but according to ancient Roman farmers' almanacs Juno was the tutelary deity of the month.

Agricultural calendars (menologia rustica) show that for farmers, January continued the relatively slack time they experienced in December.

The phase from the winter solstice to February 7, when Favonius the west wind was thought to start blowing favorably, was not for hard work, but odd jobs and tidying.

Auspices were taken, and if favorable the two consuls went home and put on their toga praetexta, with the purple stripe signifying their status.

On the calendar of the Roman Republic and early Principate, each day was marked with a letter to denote its religiously lawful status.

January had two feriae conceptivae, moveable feasts that might occur on varying days to be announced by the Roman pontiffs.

During the Imperial period, some of the traditional festivals localized at Rome became less important, and the birthdays and anniversaries of the emperor and his family gained prominence as Roman holidays.

On the calendar of military religious observances known as the Feriale Duranum, sacrifices pertaining to Imperial cult outnumber the older festivals.