Do you remember the 21st night of September?

"Do you remember the 21st night of September?"

Happy 40th anniversary to Earth, Wind & Fire's "September," which was actually released on November 18, 1978. What's the significance of September 21 in the lyrics? Well, none.

"We went through all the dates: 'Do you remember the first, the second, the third, the fourth … ' and the one that just felt the best was the 21st," co-writer Allee Willis told NPR in 2014. "I constantly have people coming up to me and they get so excited to know what the significance was. And there is no significance beyond it just sang better than any of the other dates. So … sorry!"