How are the months of the year named?

The origins of our calendar came from the old Roman practice of starting each month on a new moon. Roman bookkeepers would keep their records in a ledger called a kalendarium, from which comes the English word “calendar.” The original Roman calendar was 304 days long and had 10 months that began with March and ended with December. The Roman political leader Julius Caesar reorganized the calendar year to start with the month of January. Thus, the first month was named for Janus, the Roman god of beginnings and endings. February was named for the god of purification, Februus. March was named for Mars, the Roman god of war. April comes from the Roman word aperire, meaning “to open”; this is the month when the trees and flower buds open. May is named for Maiesta (Maia), the Roman goddess of honor and reverence. June is named for Juno, the Roman queen of the gods. July is named after Caesar himself, who was born in this month, and August is named for Augustus, the Roman emperor. And the last four months of the year have numerical meanings: September comes from the word septem, meaning “seven”; October from the word “octo,” meaning “eight”; November from the word novem, meaning “nine”; and December from the word decem, meaning “ten.”

The Roman emperor Julius Caesar was responsible for reorganizing the Western calendar so that years began with the month of January.