| 104011 | September 11 | Death | 2015 – Alan Purwin, American pilot, actor, and stuntman (b. 1961) |
| 104012 | September 11 | Death | 2015 – Kerry Simon, American chef (b. 1955) |
| 104013 | September 11 | Holiday and observance | Christian feast days:Blessed Francesco BonifacioDeiniolHarry Burleigh (Episcopal Church)John Gabriel Perboyre (one of Martyr Saints of China)Our Lady of CoromotoPaphnutius of Thebes (Roman Catholic Church)Protus and HyacinthSeptember 11 (Eastern Orthodox |
| 104014 | September 11 | Holiday and observance | Battle of Tendra Day (Russia) |
| 104015 | September 11 | Holiday and observance | Death Anniversary of Quaid-e-Azam Muhammad Ali Jinnah, a former holiday. (Pakistan) |
| 104016 | September 11 | Holiday and observance | Emergency Number Day proclaimed by President Reagan on August 26 in 1987. (United States communities, particularly the local emergency services) |
| 104017 | September 11 | Holiday and observance | Enkutatash falls on this day if it is not a leap year. Celebrated on the first day of Mäskäräm. (Ethiopia, Rastafari) |
| 104018 | September 11 | Holiday and observance | National Day of Catalonia (Catalonia) |
| 104019 | September 11 | Holiday and observance | National Hot Cross Bun Day (United States) |
| 104020 | September 11 | Holiday and observance | Nayrouz (Coptic Orthodox Church) |
| 104021 | September 11 | Holiday and observance | Patriot Day (United States) |
| 104022 | September 11 | Holiday and observance | Remember Freedom Day |
| 104023 | September 11 | Holiday and observance | Teachers' Day (Argentina) |
| 104024 | September 12 | Event | 490 BC – Battle of Marathon: The conventionally accepted date for the Battle of Marathon. The Athenians and their Plataean allies, defeat the first Persian invasion force of Greece. |
| 104025 | September 12 | Event | 372 – Sixteen Kingdoms: Jin Xiaowudi, age 10, succeeds his father Jin Jianwendi as Emperor of the Eastern Jin dynasty. |
| 104026 | September 12 | Event | 1185 – Emperor Andronikos I Komnenos brutally put to death in Constantinople. |
| 104027 | September 12 | Event | 1213 – Albigensian Crusade: Simon de Montfort, 5th Earl of Leicester, defeats Peter II of Aragon at the Battle of Muret. |
| 104028 | September 12 | Event | 1229 – Battle of Portopí: The Aragonese army under the command of James I of Aragon disembarks at Santa Ponça, Majorca, with the purpose of conquering the island. |
| 104029 | September 12 | Event | 1309 – The First Siege of Gibraltar takes place in the context of the Spanish Reconquista pitting the forces of the Kingdom of Castile against the Emirate of Granada resulting in a Castilian victory. |
| 104030 | September 12 | Event | 1609 – Henry Hudson begins his exploration of the Hudson River while aboard the Halve Maen. |
| 104031 | September 12 | Event | 1683 – Austro-Ottoman War: Battle of Vienna – several European armies join forces to defeat the Ottoman Empire. |
| 104032 | September 12 | Event | 1814 – Battle of North Point: an American detachment halts the British land advance to Baltimore in the War of 1812. |
| 104033 | September 12 | Event | 1846 – Elizabeth Barrett elopes with Robert Browning. |
| 104034 | September 12 | Event | 1847 – Mexican–American War: the Battle of Chapultepec begins. |
| 104035 | September 12 | Event | 1848 – Switzerland becomes a Federal state. |
| 104036 | September 12 | Event | 1857 – The SS Central America sinks about 160 miles east of Cape Hatteras, North Carolina, drowning a total of 426 passengers and crew, including Captain William Lewis Herndon. The ship was carrying 13–15 tons of gold from the California Gold Rush. |
| 104037 | September 12 | Event | 1885 – Arbroath 36–0 Bon Accord, a world record scoreline in professional Association football. |
| 104038 | September 12 | Event | 1890 – Salisbury, Rhodesia, is founded. |
| 104039 | September 12 | Event | 1897 – Tirah Campaign: Battle of Saragarhi. |
| 104040 | September 12 | Event | 1906 – The Newport Transporter Bridge is opened in Newport, South Wales by Viscount Tredegar. |