The word autumn originates from the ancient Etruscan root autu which became the Latin word autumnus. Before the 16th century, harvest was the term usually used to refer to the season. As people gradually moved from working the land to living in towns, the word harvest lost its reference to the time of year and came to refer only to the actual activity of reaping, and autumn, as well as fall, began to replace it as a reference to the season.
On the northern hemisphere autumn is usually considered to run from September 21 until December 20. The astronomical start is linked to the September equinox (21 to 24 September) and the end with the winter solstice (21 or 22 December).