In ancient Rome, the calendar used was known as the Roman calendar. This calendar system was based on a lunar calendar with 10 months, totaling 304 days in a year. The months in the Roman calendar were Martius, Aprilis, Maius, Junius, Quintilis, Sextilis, September, October, November, and December. The year began in March, with Martius being the first month.
Julius Caesar, the Roman dictator, introduced the Julian calendar in 46 BC to address the inaccuracies in the Roman calendar. The Julian calendar added two new months, January and February, to make a total of 12 months in a year. This reform also included the addition of a leap year every four years to account for the extra quarter of a day in the solar year.
Pre-julian Calendar Months
Transition Period
During the transition from the Roman calendar to the Julian calendar, the original 10 months were renamed and rearranged. Quintilis was renamed Julius in honor of Julius Caesar, and Sextilis was renamed Augustus in honor of Caesar Augustus. This change resulted in the months of September, October, November, and December, which mean the seventh, eighth, ninth, and tenth months in Latin, being pushed back to become the ninth, tenth, eleventh, and twelfth months.