School starts in September in many countries, such as here, in Belgium
WPA poster, 1940

September is the ninth month of the year in the Julian and Gregorian calendars and the third month to have the length of 30 days. In the Northern Hemisphere September is the seasonal equivalent of March in the Southern Hemisphere.

In the Northern hemisphere, the beginning of the meteorological autumn is on 1 September. In the Southern hemisphere, the beginning of the meteorological spring is on 1 September.[2] 

September marks the beginning of the ecclesiastical year in the Eastern Orthodox Church. It is the start of the academic year in many countries, in which children go back to school after the summer break, sometimes on the first day of the month.

September (Roman month) (from Latin septem, "seven") was originally the seventh of ten months on the oldest known Roman calendar, with March (Latin Martius) the first month of the year until perhaps as late as 153 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.

Ancient Roman observances for September include Ludi Romani, originally celebrated from September 12 to September 14, later extended to September 5 to September 19. In the last 1st century BC, an extra day was added in honor of the deified Julius Caesar on 4 September. Epulum Jovis was held on September 13. Ludi Triumphales was held from September 18–22. The Septimontium was celebrated in September, and on December 11 on later calendars. These dates do not correspond to the modern Gregorian calendar. In 1752, the British Empire adopted the Gregorian calendar. In the British Empire that year, September 2 was immediately followed by September 14.

September was called "harvest month" in Charlemagne's calendar. September corresponds partly to the Fructidor and partly to the Vendémiaire of the first French republic. On Usenet, it is said that September 1993 (Eternal September) never ended. September is called Herbstmonat, harvest month, in Switzerland. The Anglo-Saxons called the month Gerstmonath, barley month, that crop being then usually harvested.

September in Astronomy and Astrology

Meteor showers that occur in September include the Aurigids, the Delta Aurigids which occur from mid-September to early October, the Southern Taurids, which occur from September 10 to November 20, and the Andromedids which occur from September 25-December 25.

The September equinox takes place in this month, and certain observances are organized around it. It is the Autumn equinox in the Northern Hemisphere, and the Vernal Equinox in the Southern Hemisphere. The dates can vary from 21 September to 24 September (in UTC).

September is mostly in the sixth month of the astrological calendar (and the first part of the seventh), which begins at the end of March/Mars/Aries.

September symbols


This list does not necessarily imply either official status or general observance.

Non-Gregorian observances, 2017

(please note that all Jewish observances, which are set by the Hebrew calendar, begin at sunset the day prior to the date listed and end on the nightfall of the date in question)

Month-long observances

United States observances

Food Months

Movable Gregorian Observances, 2017 dates

First Friday: September 1

First Sunday: September 3

Week of the First Monday: September 3-9

First Monday: September 4

First Wednesday: September 6

First Thursday: September 7

Thursday after the first Sunday: September 7

Saturday after first Monday: September 9

Second Saturday: September 9

Weekend after first Monday: September 8-10

Week of September 10: September 10-16

First Sunday after September 4: September 10

Second Sunday: September 10

First Sunday after first Monday:September 11

Nearest weekday to September 12: September 12

Third Friday: September 15

Third Saturday: September 16

Weekend of the Week of September 17: September 16-17

Week of September 17: September 17-23

Week of September 22: September 17-23

Week of Sunday before September 23: September 17-23

Third Sunday: September 17
Weekday nearest September 17: September 18
September 17 but observed on previous Friday if it falls on a Saturday or following Monday if on a Sunday: September 18
Monday after third Sunday: September 18
Third Monday: September 18
Third Tuesday: September 19
Observances pertaining to the September Equinox: September 22
Fourth Friday: September 22
Saturday closest to September 23: September 23

Last week: September 24-30

Last full week: September 24-30

Last Week of the Month: September 24-30

Last Sunday: September 24
Fourth Monday: September 25
Last Wednesday: September 27
Last weekday in September: September 29
Last Friday: September 29
Last Saturday: September 30

Fixed Gregorian observances