The Roman Origins of Month Names: From Janus to December
The months' names trace back to the ancient Romans, who developed the calendar system that eventually became the Gregorian Calendar, which approximately 90 percent of the global population will use in 2026. Initially, the Roman calendar, established around 753 BC, consisted of ten months, with January and February later introduced by King Numa Pompilius. In 1582, Pope Gregory XIII implemented the Gregorian Calendar to rectify the leap year inaccuracies of the Julian Calendar. January derives its name from Janus, February from 'Februarius,' March commemorates Mars, and April likely comes from 'aperire.' The origins of May are unclear, while June is named for Juno. July and August honor Julius and Augustus Caesar, and September through December reflect their original numerical order. Cultural events include Valentine's Day, Halloween, and Saturnalia.
Key facts
- The Gregorian Calendar, introduced by Pope Gregory XIII in 1582, is used by about 90% of the world's population in 2026.
- The first Roman calendar, created around 753 BC, had only ten months; January and February were added by King Numa Pompilius.
- January is named after Janus, the Roman god of beginnings, gates, and transitions.
- February comes from 'Februarius,' meaning purification, and was a time for ritual cleansings and the festival Februalia.
- March is named after Mars, the Roman god of war and agriculture, and was originally the first month in the early Roman calendar.
- April likely derives from 'aperire' (to open), and was associated with Venus.
- May's name may come from Maia, goddess of earth and fertility, or from 'majores' (elders) as suggested by Ovid.
- June is named after Juno, goddess of marriage and childbirth, making it a traditional month for weddings.
- July and August are named after Julius Caesar and Augustus Caesar.
- September, October, November, and December are named after the Latin numbers septem (7), octo (8), novem (9), and decem (10).
Entities
Artists
- Jacobus Harrewyn
- Diego Velázquez
- Jan Davidsz de Heem
- Bartholomeus Spranger
- Luigi Mayer
- Lionel Royer
- Giovanni Battista de'Cavalieri
- Limbourg Brothers
- Jennie Augusta Brownscombe
- Dante Gabriel Rossetti
- Bartolomeo Passarotti
Institutions
- Encyclopaedia Britannica
- The British Museum
- Museo del Prado
- Mauritshuis
- Kunsthistorisches Museum
- Library of Trento
- Wikimedia Commons
Locations
- Rome
- Italy
- Tunisia
- El Jem
- Samos
- Greece
- Plymouth
- United States