You may have noticed that two versions of the name are found throughout the atlas– Septembrila and Septembrilan. This is a remnant of the divide that once existed due to the Septimus mountain range. Both names are still used, with dominance varying by region.
In Latin, septem means "seven" and septimus means "seventh"; September was in fact the seventh month of the Roman calendar until 153 BC, when the first month changed from Kalendas Martius (1 March) to Kalendas Januarius (1 January).  In the Northern hemisphere, the beginning of the meteorological autumn is 1 September
Autumn (also known as fall in North American English) is one of the four temperate seasons. Autumn marks the transition from summer into winter, usually in March (southern hemisphere) or September (northern hemisphere) when the arrival of night becomes noticeably earlier.
There are six bright stars that are distinctly of the winter– Aldebaran, Betelgeuse, Regel, Pollux, Procyon and Sirius. Of these 6 stars, Aldebaran is the first to appear in September a bit north of the east point in the horizon. It glows with rosy light, demanding attention proclaiming as one of the most importantly heavenly bodies.
River Yom Kippur
Yom Kippur, also known as the Day of Atonement, is the holiest day of the year for religious Jews. Its central themes are atonement and repentance. Jews traditionally observe this holy day with a 25-hour period of fasting and intensive prayer, often spending most of the day in synagogue services. Yom Kippur completes the annual period known in Judaism as the High Holy Days.
Named for Labor Day, a United States federal holiday observed on the first Monday in September. The holiday originated in Canada out of labor disputes ("Nine-Hour Movement") first in Hamilton, then in Toronto, Canada in the 1870s, which resulted in a Trade Union Act which legalized and protected union activity in 1872 in Canada. In 1882, American labor leader Peter J. McGuire, inspired from Canadian events in Toronto, returned to New York and organized the first American "labor day" on September 5 of the same year.
In the Netherlands the third Tuesday in September is known as prinsjesdag. The government presents its annual budget; the queen rides to the parliament in a gilded coach and reads the plans for the coming year to the States-general.
Nmaed for September's birthstone, the sapphire. The meaning is clear thinking.