1. September, often abbreviated as Sep. in English, is the ninth month of the Gregorian calendar and has 30 days. The name "September" comes from the Latin word "septem", which means "seven".

2. September was originally the seventh month of the Roman calendar, as it was the seventh month counted from March. However, when January and February were added to the calendar, September became the ninth month.

3. In many parts of the world, September marks the beginning of autumn, or fall, and the end of summer. The weather begins to cool down, leaves start changing color, and students return to school.

4. In the United States, September is also known as National Preparedness Month, a time for individuals and communities to prepare for potential disasters and emergencies.

5. There are several holidays and observances that occur in September, including Labor Day in the United States, which celebrates the contributions and achievements of workers, and International Literacy Day, which promotes literacy around the world.

6. September is also a popular month for weddings, as the weather begins to cool and the colors of fall make for a beautiful backdrop.

7. Overall, September is a month of transition and preparation, a time to say goodbye to summer and get ready for the coming autumn.