For many, the month of September signals the end of summer, the beginning of autumn, and the start of a new school year. With respect to the calendar, September marks the beginning of the months that signify nothing other than their numerical position in the year. September comes from the Latin root septem- , meaning “seven,” because in the original Roman republican calendar September was the seventh month of the year rather than the ninth. The Roman calendar was only ten months long and included the following months—Martius, Aprilis, Maius, Junius, Quintilis, Sextilis, September, October, November, and December. The last six months were assigned names according to their ordinal numbers—Quintilis is the fifth month, Sextilis is the sixth month, and so on. It wasn’t until 45 BC, when Julius Caesar introduced the Julian calendar (named after Caesar, himself), that the year grew to include two more months, January and February. Quintilis and Sextilis ...