Quintilis

Quintilis, from the Latin quintilis meaning “fifth,” was the fifth month of the early Roman ten-month calendar, which began in March. Its name reflected its position in the year rather than any deity, and it roughly corresponds to July in the modern Gregorian calendar.

In the wake of Julius Caesar’s calendar reform, the year was restructured into a 12-month system. Quintilis was renamed Iulius (July) in honor of Julius Caesar, a change that effectively moved the month into its current position as July in the modern calendar. A later reform also renamed Sextilis to Augustus, giving us August in honor of Emperor Augustus. These renamings explain why the modern months July and August bear the names of two Roman leaders, rather than the earlier Quintilis and Sextilis.

The name Quintilis fell out of common use after the renaming, though it continues to appear in historical texts and Latin discussions of the Roman calendar. In scholarly contexts, Quintilis is used to reference the old configuration of the Roman year and to illustrate the transition from the ancient ten-month system to the Julian calendar. The modern calendar retains the legacy of Quintilis only in the etymology of July, while the daily practice of timekeeping ultimately follows January–December.