September (from Latin septem, "seven") was originally the seventh of ten months in the oldest known Roman calendar, the calendar of Romulus c. 750 BC, with March (Latin Martius) the first month of the year until perhaps as late as 451 BC.
After the calendar reform that added January and February to the beginning of the year, September became the ninth month but retained its name. It had 29 days until the Julian reform, which added a day.
September's birthstone is the sapphire.
The birth flowers are the forget-me-not, morning glory and aster.
The zodiac signs are Virgo (until September 22) and Libra (September 23 onward).
