Chimney Day is a unique internet phenomenon that originated from a Reddit post in early 2018, which proposed that everyone post pictures of chimneys on April 6, 2019, to confuse anyone not in on the joke. When the day finally arrived, subreddits were flooded with images of industrial, brick, and residential chimneys, leaving casual browsers utterly bewildered. This collective act of digital performance art represents the internet's love for coordinated, nonsensical humor. Today, the Chimney Day meme lives on as a symbol of deep-web inside jokes and the power of scheduled viral events.