Januarius, Februarius, Mars, Aprilis? How Each Month Got Its Name

By: Carrie Tatro  | 
Our lives are divided into monthly segments of time, but how did we decide what to call each month? ELUTAS/Shutterstock

Buckle up, earthlings. Every year we go on another 365-day, five-hour, 59-minute and 16-second revolution around the sun. Einstein said that time is an illusion — that whether we’re young or old, time flies or crawls depending on our own individual frames of reference. Most of us humans have a lot of stuff to do and are too busy getting it done to ponder infinity and the illusory nature of time. But have you ever wondered how the calendar came to be? Or why the first month of the year is called January? Or why Nevuary definitely should be, but isn’t, a month at all?


Our Calendar Is the Gregorian Calendar

The Gregorian calendar — aka the Christian or Western calendar — is currently the most broadly used international calendar for measuring time. Introduced by Pope Gregory XIII in 1582, it's a 356-day solar calendar that is divided into 12 months. The Gregorian calendar reformed and replaced the Julian calendar (introduced by Julius Caesar in 45 B.C.E.), which bungled the calculation of the time it takes for our big blue marble to orbit the sun.


The Gregorian Calendar Came From the Roman Calendar

And before that, there was the Roman calendar upon which our current Gregorian calendar is based. The Roman calendar was a super-complicated lunar calendar that had 12 months but only 10 of them had formal names. Why? Because winter was considered a dead, inactive time of year and a season meant for rest. So, thanks to Romulus, the legendary first king of Rome in 735 B.C.E., only March through December were deemed fit to name. The Roman calendar was eventually reformed, adding Januarius and Februarius as the last two months of the year.


How Each Month Got its Name

Interestingly, in a way, our lives are run by ancient Rome: The names of our months are derived from Roman gods, Roman leaders, Roman festivals and rituals, and even Roman numerals. So, as Earth spins on its axis toward another day, read on for a nutshell version of how the months got their names.


The Roman month of Januarius takes its name from the Roman god Janus, the protector of gates and doorways. Janus is typically depicted with two faces — one looking into the past, the other looking into the future. The gates to the temples of Janus were left open in times of war and closed during times of peace.



Based on the Latin word februa, meaning "to cleanse," the Roman month of Februarius is named for Februalia, a Roman festival of purification and atonement. Februarius, at some point in time, was shortened to February.


Named for Mars, the Roman mythological god of war, March is named for the time of year when military campaigns resumed after the dead and inactive period of winter. March was also a season of many festivals relating to the preparation of military campaigns.


Aprilis derived its name from the Latin word aperire or aperio, meaning "to open" or "bud." Invoking images of spring blossoms and the spirit of renewal, Aprilis ultimately evolved into April.


Named for the nurturing Roman earth goddess Maia, who watched over the growth of plants, May also derives from the Latin word maiores meaning "elders," who were celebrated during this month of spring.


June is inspired by the Roman goddess Juno, the patroness of marriage, childbirth and the overall wellbeing of women. Juno is the mythological wife of Jupiter, king of the Roman pantheon. June also derives from the Latin word juvenis meaning "young people."

Our years are split into months, weeks, days, hours, minutes and seconds — the names we call our months are our guideposts.


Originally named for the Latin word quintilis, meaning the number five. Changed after his death to honor the Roman dictator, Julius Caesar (100 B.C.E.–44 B.C.E.). It's important to note that he is the Julius behind the Julian calendar which he helped develop — the precursor to today's Gregorian calendar.


Like the origins of July, August was named to honor a famous political figure, the first Roman emperor, Augustus Caesar (63 B.C.E.–14 C.E.), grandnephew of Julius Caesar. Augustus derives from the eponymous Latin word, meaning, "noble, venerable and majestic."


September derives from the Latin word septem, or "seven" because it was the seventh month in the early Roman calendar.


From the Latin word octo, meaning "eight," because, you guessed it, October was the eighth month of the year in the before-times of the early Roman calendar. Attempts were made to rename it after various Roman emperors once they converted to a 12-month calendar, but for reasons unknown, their efforts fell flat.


If you can count to ten in Latin, you've probably noticed a pattern here. From the Latin word novem, meaning "nine," November takes its name because, well, November was the ninth month of the early Roman calendar.


And, it's a wrap. The Latin word decem, meaning "ten," became the month of December, the tenth month in the early Roman calendar.