Julian Calendar

  • Julian calendar - Wikipedia
    The Julian calendar is a solar calendar that was introduced in 45 BCE by Julius Caesar as a reform of the Roman calendar.

The only difference between the Gregorian and Julian calendars is that the Gregorian reform omitted a leap day in three centurial years every 400 years and left the leap day unchanged.

Gregorian Calendar

The Gregorian calendar is the calendar used in most parts of the world. It was introduced on February 24 with a papal bull, and went into effect in October 1582 by Pope Gregory XIII as a modification of, and replacement for, the Julian calendar.

The principal change was to space leap years differently so as to make the average calendar year 365.2425 days long, more closely approximating the 365.2422-day ‘tropical’ or ‘solar’ year that is determined by the Earth’s revolution around the Sun.


The names of the months reflect a mix of gods and goddesses, rulers, and numbers.

  • January: Named after Janus, the Roman god of beginnings and endings. Janus presided over doors and gates, which feels appropriate for the new year.

  • February: Named after a Roman purification festival called Februa, which occurred around the fifteenth of this month. Februa literally means “month of cleansing” .

  • March: Named after Mars, the Roman god of war. Several festivals of Mars took place in March because that was the earliest month of the year when the weather was mild enough to start a war. At one time, March was the first month in the Roman calendar.

  • April: Thought to stem from Latin aperio, meaning “to open”—possibly because it is the month in which the buds begin to open.

  • May: Named after Maia, the goddess of growth of plants.

  • June: Named after Juno, the goddess of marriage and the wife of Jupiter.

  • July: Named after Julius Caesar in 44 B.C. .

  • August: Named after Augustus Caesar in 8 B.C. .

  • September: Comes from the Latin word septem, meaning “seven,” because it was the seventh month of the early Roman calendar.

  • October: Comes from the Latin word octo, meaning “eight,” because it was the eighth month of the early Roman calendar.

  • November: Comes from the Latin word novem, meaning “nine,” because it was the ninth month of the early Roman calendar.

  • December: Comes from the Latin word decem, meaning “ten,” because it was the tenth month of the early Roman calendar.

  • Greeks