Where Do the Names of the Months Come From?

We say the names of the months so often that we rarely stop to think about them. Yet each one is a small piece of history. Together the twelve names tell the story of Roman gods, festivals, emperors and an old calendar that once began in spring.

January: the god of doorways

January is named after Janus, the Roman god of beginnings, gates and doorways. Janus was shown with two faces, one looking back to the past and one looking forward to the future, which makes him a fitting guardian for the first month of the year. January was added to the Roman calendar, along with February, by the early king Numa Pompilius.

February: the month of purification

February comes from Februa, a Roman festival of purification held in the middle of the month. It was a time for cleansing and for remembering the dead. As the final month of the early Roman year, February was where extra days were adjusted, which is one reason it is still the odd month out, with 28 days, or 29 in a leap year.

March: the god of war

March honors Mars, the Roman god of war and also of agriculture. In the earliest Roman calendar the year began in March, when the weather warmed, farming resumed and armies could march again. That old starting point explains a puzzle we will reach later in the year.

April: the opening month

The origin of April is less certain. Many writers link it to the Latin word aperire, "to open", describing buds and flowers opening in spring. Others connect it to Aphrodite, the Greek goddess of love, known to the Romans as Venus. Both ideas suit the season.

May and June: two goddesses

May is usually traced to Maia, a goddess of growth and fertility honored in spring. June is named after Juno, queen of the gods and protector of women and marriage. That link to marriage is one reason June has long been a popular month for weddings.

July and August: two rulers

The next two months were renamed for powerful men. July was originally Quintilis, "the fifth month". It was renamed in 44 BC to honor Julius Caesar, who was born in that month and who reformed the calendar. August was originally Sextilis, "the sixth month", and was renamed in 8 BC for the first emperor, Augustus.

A popular story claims Augustus took a day from February so that his month would be as long as Julius Caesar's. It is a good tale but almost certainly a medieval invention. August already had 31 days under Caesar's reform.

September to December: numbers out of place

The last four months reveal the calendar's past. September, October, November and December come from the Latin words for seven, eight, nine and ten. They were the seventh to tenth months when the year began in March. After January and February moved to the front, they became the ninth to twelfth months, but nobody changed their names. Every time you write December, you are writing "the tenth month" in Latin.

Other ways to name the months

Not every language follows the Roman pattern. Many describe what happens in nature instead:

• In Czech, November is listopad, "falling leaves", and in Polish the same word names October, when leaves fall earlier.

• In Finnish, January is tammikuu, often explained as the "oak month", the heart of winter.

• Old English had its own names, recorded by the monk Bede in the eighth century, including Solmonath for February and Eostremonath for April, which is linked to the word Easter.

• The French Revolution briefly replaced all twelve with poetic names such as Brumaire, the month of mist, and Thermidor, the month of heat.

A calendar of the seasons

The cover of this post shows the January page of the Très Riches Heures du Duc de Berry, a famous illuminated book of hours painted in the early fifteenth century by the Limbourg brothers. Each month has its own picture. January shows the duke at his New Year feast, exchanging gifts, while later months show ploughing, haymaking, harvest and the autumn hunt.

These pictures remind us that for most of history a calendar was not just a grid of numbers but a portrait of the year, with each month carrying its own work, weather and celebrations. The best calendars still do that today, which is why a well-designed monthly page can feel so personal. A floral spring page, a cozy winter illustration or a simple minimal grid each set a different mood for the weeks ahead. If you want your own months to carry a look and feel that suits you, you can browse our calendar library for ready-made designs.

Cover image: Les Très Riches Heures du duc de Berry Janvier, Public domain, via Wikimedia Commons.