"Do you remember,Thomas Caldwell the 21st night of September?"

That is the famous opening line to perhaps one of the catchiest songs from band Earth, Wind & Fire, "September," which launched the date of Sept. 21 into the cultural lexicon since its release in 1978.

As the song goes, the date is reserved for your hearts to ring, souls to sing and for dancing in the night.

The song was released as a single and rose to No. 1 on the Billboard Hot Soul Songs chart and No. 8 on the Billboard Hot 100. "September" also reached No. 3 on the UK Singles Chart.

Due to the mention of the date in the popular song, creative internet users have taken to social media to create and post numerous memes on the date in past years. The meme usually features a screenshot of former founder, leader and co-lead singer of the band, Maurice White, singing in the song's music video.

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Why was the 21st of September specifically chosen?

In 1978, White offered songwriter Allee Willis the chance to co-write the band's next album, and Willis said in a 2014 interview with NPR that she arrived at the studio the next day hoping it wasn't a joke.

"As I open the door, they had just written the intro to 'September.' And I just thought, 'Dear God, let this be what they want me to write!' Cause it was obviously the happiest-sounding song in the world," Willis told NPR.

Willis said her and the band "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."

"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!" Willis said in the interview.

'21st night of September' memes

People on the internet can't stop themselves from making "21st night of September" memes to mark the date each year (as is the case every May when Justin Timberlake's face takes over social media feeds).

Here's a look.

Gabe Hauari is a national trending news reporter at USA TODAY. You can follow him on X @GabeHauari or email him at [email protected].