Dayman comes from It's Always Sunny in Philadelphia, where Charlie Kelly writes the song for his musical The Nightman Cometh in a 2008 episode. In the story Dayman is the heroic opposite of the Nightman, champion of the sun and a master of karate and friendship. Fans turned the sung ahh-ahh-ahh refrain into a standalone reaction clip, sharing it on soundboards and in edits whenever someone needs an absurdly heroic introduction out of proportion to the moment.