December (Roman month) December (Roman month) December (from Latin "decem", "ten") or mensis December was originally the tenth month of the Roman calendar, following November ("novem", "nine") and preceding Ianuarius. It had 29 days. When the calendar was reformed to create a 12-month year starting in Ianuarius, December became the twelfth month, but retained its name, as did the other numbered months from Quintilis (July) through December. Its length was increased to 31 days under the Julian calendar reform. The Romans did not number days of a month sequentially from the first day through the last. Instead, they counted back from the three
September (Roman month) the Republican era, and in the earliest period, the consuls took office on the Ides of September. The month was often represented in art by the grape harvest. September was the birth month of no fewer than four major Roman emperors, including Augustus. The emperor Commodus renamed the month after either himself or Hercules—an innovation that was repealed after his murder in 192. In the Eastern provinces of the Roman Empire, the year began with September on some calendars, and was the beginning of the imperial tax year. For the month of September, ancient farmers' almanacs "(menologia rustica)" take note