Origin of Month Names

We mark time in many different ways – months, weeks, days, seconds. These terms get thrown around regularly, and they play a huge role in the way we conceptualize the many happenings of our lives.

The months’ names reflect a mix of gods and goddesses, rulers, and numbers. Discover how our calendar developed into what it is today.

How Our Calendar formed.

The Ancient Roman Calendar

Today, we follow the Gregorian calendar, but it’s based on the ancient Roman calendar, believed to be invented by Romulus, who served as the first king of Rome around 753 BC.

The Roman calendar, a complicated lunar calendar, had 12 months like our current calendar, but only 10 of the months had formal names.

Julian Calendar Updates

When Julius Caesar became pontifex maximus(head of the administration), he reformed the Roman calendar so that the 12 months were based on Earth’s revolutions around the Sun. It was a solar calendar as we have today. January and February were moved to the front of the year, and leap years were introduced to keep the calendar year lined up with the solar year.

Today’s Gregorian Calendar

Quite a bit later, in 1582, Pope Gregory XIII introduced a number of reforms to the Julian calendar, as there were still some inaccuracies and adjustments to be made. Mainly, the Julian calendar had overestimated the amount of time it took the Earth to orbit the Sun, so the Gregorian calendar shortened the calendar year from 365.25 days to 365.2425 days. This meant that the calendar could be more easily corrected by leap years and that the dates of the equinoxes and solstices (equinoxes means time or date(twice each year) at which the sun crosses the celestial equator, when day and night are of approximately equal length (about 22 September and 20 March )

solstices means the time or date (twice each year) at which the sun reaches its maximum or minimum declination, marked by the longest and shortest days (about 21 June and 22 December).

January

January is named after Janus, the Roman god of beginnings and endings. Janus presided over doors and gates, which feels appropriate for the new year. He is often depicted with two faces – one looking forward and the other looking backward. Notably, January was the last month to be added to the calendar, which originally had ten months and began in March.

February

February is named after a Roman purification festival called februa, which occurred around the fifteenth of this month. Februa literally means “month of cleansing” – a fitting title considering that February was once the last month of the year. Much like the New Year’s Resolutions of today, a “month of cleansing” seems like a good way to say goodbye to the old and usher in the new.

March

March is named after Mars, the Roman god of war. In ancient Rome, war was ceased during the time of celebration between the old and new year. Since March was the earliest part of the year when the weather was mild enough to begin waging war again, it was originally the first month.

April

There are a few different theories about where April gets its name. Some believe that April is derived from the Latin base apero – meaning “second” – because it was once the second month of the year. Others say it comes from another Latin word, aperire, which means “to open” and is suggestive of the opening of buds and flowers during springtime. Still others claim that April was named for Aphrodite, the Greek goddess of love, beauty, and procreation.

May

May is named for the Greek goddess Maia. She had a son, Hermes, with the god Zeus, and she was an earth goddess and a goddess of growth, which explains her connection to this springtime month.

June

June is named after Juno, the wife of Jupiter and queen of the gods. Juno was the patroness of childbirth and marriage, which is fitting for what has long been the most popular month for weddings.

July

July was the birth month of Julius Caesar, for whom the month was renamed following his death in 44 B.C. Previously, July was called “Quintilis,” which is Latin for “fifth” and referred to the fact that, with the calendar year beginning in March, July was the fifth month. July was also the first month to be named after a real person, rather than a Roman or Greek deity.

August

August is the only other month named after a historical figure – Augustus Caesar, who was the nephew of Julius Caesar and the first emperor of Rome. Much like July, August was previously called “Sextilius,” meaning – you guessed it – “sixth.” It was Emperor Augustus’ legacy which eventually gave rise to the adjective august, meaning “respected and impressive.” Additionally, July and August were both allotted thirty-one days to reflect the importance of the leaders that they represented.

September, October, November, December

September, October, November, and December come from the Latin words septem, octo, novem, and decem, meaning “seventh,” “eighth,” “ninth,” and “tenth.” Though their root meanings now make them feel out of place in the calendar year, prior to the addition of January and February, they were indeed the seventh, eighth, ninth, and tenth months.

SEPTEMBER

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

OCTOBER

In the ancient Roman calendar, October was the name of the eighth month of the year. Its name comes from octo, the Latin word for “eight.” When the Romans converted to a 12-month calendar, they tried to rename this month after various Roman emperors, but the name October stuck.

NOVEMBER

From the Latin word novem, “nine,” because this had been the ninth month of the early Roman calendar.

DECEMBER

From the Latin word decem, “ten,” because this had been the tenth month of the early Roman calendar.