Where we get the twelve English names for the months of the year.
As with many words in English, the twelve words we use for the twelve months come from Latin. Strangely enough, though, the ancient Romans had only ten months for a while. Over the centuries, other calendars have been introduced, evolving into the one we use today.
The Ten Roman Months
Centuries ago, around 753 BC, it’s believed that Romulus, the first king of Rome, invented the original, pre-Julian, Roman calendar, which was probably a lunar calendar, meaning it was based on the cycles of the moon. This calendar had ten months covering 304 days. The months were named Martius, Aprilis, Maius, Iunius, Quintilis, Sextilis, September, October, November, and December. (1)
The first four Roman months sound less familiar than the later ones. The names of Roman gods and goddesses figure into three of the four names: Martius was named for Mars, the god of war; (2) Maius comes from Maia, the goddess who “oversaw the growth of plants”; (3) and Iunius comes from Juno, “patroness of marriage and the well-being of women.” (3) Aprilis is the odd one out, likely coming from aperire, the Latin word for “open.” Aprilis was so named “because it is the month in which the buds begin to open.” (2) Incidentally, another English word that comes from aperire is aperture, which refers to a small opening such as a hole or a gap. (4)
The names of the last six months in the Roman calendar—Quintilis through December—seem strictly number based. Quintilis starts with quint, meaning “five,” as in the word quintuplets, referring to five babies born at once. Likewise, Sextilis, relates to the number six, as in the word sextuplets. You won’t be surprised to learn that the months September through December originate from the Latin septem, octo, novem, and decem, the numbers seven through ten, respectively. (2)