Here’s how every month got its name

Wordymology is a series in which the editors at The Free Dictionary explore the origins of the names of things.
Whether they’re on our phones, in our planners, or on our walls, calendars are our constant companions. Our lives are governed by the months of the year, but do we ever really think about them? Why are the months’ names what they are? What do they mean? And why do so many of them not make sense?
Join us on a journey through the calendar pages to answer these questions and more!


Did you know that, in ancient Rome, the calendar was only 10 months long, and extra days or months could be inserted when needed? It’s true, and January and February were not among those original 10 months. They were added later—at the end of the year!
“January” is named after Janus, the Roman god of beginnings, which would have been pretty awkward if January had stayed at the end of the year!


February gets its name from Februa, an ancient Roman festival of purification held on February 15. The month’s Latin name, Februārius mēnsis, means “month of purification.”


Happy New Year! In the Roman calendar, the new year started in March. It also, apparently, came in like a lion, because “March” comes from the Latin word Mārtius, meaning “of Mars,” as in, the Roman god of war (who also lent his name to one of the days of the week).


And the award for “Most Mysterious Etymology” goes to April! Its Latin name is aprīlis, but the reason why remains a source of debate. One popular theory is that aprīlis is related to the Latin word aperīre, meaning “to open,” a reference to the blooming flowers of spring.


Let’s not forget May flowers, though. The name “May” is thought to refer to Maia, the Roman goddess of fertility.


There are two possible explanations for the name “June.” It might be in honor of Juno, the queen of the Roman gods. Or it might come from Jūnius, which was the name of a particular Roman gens—a group of families in ancient Rome who shared a name and claimed descent from a common male ancestor.


The ancient Romans originally used a different name for “July”—Quintilis, which referred to its position as the fifth month of the year, back when March was the first month (the prefix “quint-” means “five”). But Quintilis was later renamed Iūlius or Jūlius in honor of Julius Caesar. In addition to being emperor and all that, Caesar introduced the “Julian calendar,” which added a leap year every four years and fixed the length of the year at 365 or 366 days. (The things some people will do to get a month named after them, sheesh.)


August was formerly the sixth month and, as such, was known as Sextilis (the prefix “sex-” means “six”). Now, though, it bears the name of Caesar’s grandnephew, the emperor Augustus.


As we saw with Quintilis and Sextilis, the Romans named some months for their numerical position in the calendar. These names were rendered incorrect once January and February were moved to the beginning of the year, and yet, they were never changed. So our ninth month has the name "September,” which comes from septem, the Latin word for “seven.”


The same fate befalls our tenth month, October. If you know words like “octopus” and “octagon,” then you already know that the Latin word octō means “eight.”


In Latin, novem means “nine,” which was a perfect fit when November was the ninth month of year.


And, as you might have expected, “December” draws upon the Latin word for 10, which is decem.
But where does the -ber come from? It likely originates in membris, a suffix deriving from mēnsis, a Latin word for “month” that is also related to the word for the original calendar inspiration—the moon.
How would you rename the months?
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