| September 1, 2024 | National Nutrition Week |
| September 2, 2024 | World Coconut Day |
| September 5, 2024 | International Day of Charity, Teacher's Day, Hartalika Teej |
| September 7, 2024 | International Vulture Awareness Day, Ganesh Chaturthi, Brazilian Independence Day |
| September 8, 2024 | International Literacy Day, World Physical Therapy Day |
| September 10, 2024 | World Suicide Prevention Day |
| September 11, 2024 | 9/11 Remembrance Day, National Forest Martyrs Day |
| September 13, 2024 | International Chocolate Day |
| September 14, 2024 | Hindi Diwas, World First Aid Day |
| September 15, 2024 | International Day of Democracy, Onam, National Engineer Day |
| September 16, 2024 | Malaysia Day, World Ozone Day |
| September 17, 2024 | World Patient Safety Day |
| September 18, 2024 | World Bamboo Day |
| September 19, 2024 | International Talk Like a Pirate Day |
| September 21, 2024 | International Day of Peace, World Alzheimer's Day, International Red Panda Day |
| September 22, 2024 | World Rhino Day, World Rivers Day |
| September 23, 2024 | International Day of Sign Languages |
| September 25, 2024 | World Pharmacists Day, Antyodaya Day |
| September 26, 2024 | European Day of Languages, Day of the Deaf, World Contraception Day, World Environmental Health Day |
| September 27, 2024 | World Tourism Day, Google Birth Anniversary |
| September 28, 2024 | World Rabies Day, International Day for Universal Access to Information |
| September 29, 2024 | World Heart Day |
| September 30, 2024 | International Translation Day |
