The names of our 12 months are essentially a miniature history of ancient Rome.
Some are named after gods, some after rulers, and—most interestingly—September through December are simply numbers that no longer match their positions because the Roman calendar changed.
| Month | Origin | Literal meaning / story |
|---|---|---|
| January | Latin Ianuarius, from Janus | Named for the Roman god Janus, god of beginnings, transitions, gates, and doorways. He was often depicted with two faces, looking backward and forward—fitting for the start of a new year. |
| February | Latin Februarius, from februa | Connected with purification. The Romans held purification rites called Februa during this month. |
| March | Latin Martius, from Mars | Named after Mars, the Roman god of war. March was originally the first month of the early Roman calendar, when military campaigning resumed after winter. |
| April | Latin Aprilis | Origin is uncertain. Traditionally associated with Latin aperire, “to open,” referring to flowers and plants opening in spring. This explanation is attractive but not certain. |
| May | Latin Maius, probably from Maia | Probably named for Maia, a Roman/Italic goddess associated with growth and fertility. |
| June | Latin Iunius, probably from Juno | Usually connected with Juno, Roman goddess of marriage and women and wife of Jupiter. |
| July | Latin Iulius | Originally called Quintilis, meaning “fifth month.” It was renamed in honor of Julius Caesar, who was born in this month. |
| August | Latin Augustus | Originally Sextilis, meaning “sixth month.” It was renamed in honor of Emperor Augustus. |
| September | Latin septem | “Seven.” September was originally the 7th month. |
| October | Latin octo | “Eight.” October was originally the 8th month. Compare octopus—eight feet/arms. |
| November | Latin novem | “Nine.” November was originally the 9th month. |
| December | Latin decem | “Ten.” December was originally the 10th month. Compare decimal and decade. |
Why are September–December “off by two”?
This is the fascinating part.
The traditional early Roman calendar began with March, not January:
1. March
2. April
3. May
4. June
5. Quintilis
6. Sextilis
7. September
8. October
9. November
10. December
That makes the names perfectly logical:
septem → 7 → September
octo → 8 → October
novem → 9 → November
decem → 10 → December
January and February were later placed before March in the Roman calendar, eventually making September the 9th month—but the old numerical names survived.
There is another neat sequence hidden here:
Quintilis = fifth → July
Sextilis = sixth → August
September = seventh
October = eighth
November = ninth
December = tenth
Only the first two numerical names were replaced—Quintilis by Julius Caesar’s name and Sextilis by Augustus’s name. If the Romans hadn’t renamed them, we might today have something resembling Quintember, Sextember, September, October, November, December.
So every time you say September, October, November, December, you’re carrying around a linguistic fossil from a calendar that began the year in March more than two thousand years ago.
