September was released in 1978 by Earth, Wind & Fire, written by Maurice White, Al McKay and Allee Willis for the band's greatest hits collection. The song's question about the 21st night of September became one of pop music's most quoted hooks, even though the date was chosen mainly for how it sang. It returned every autumn on radio and social media, then spread further through films, adverts and short form edits. Its upbeat disco funk sound now signals nostalgia and celebration far beyond its original chart run.