Bell-Bottoms Day is an unofficial holiday celebrated worldwide every April 5, dedicated to the iconic style of bell-bottomed pants. This fashion, which originated in the 19th century with sailors in the Royal Navy and U.S. Navy, gained popularity in the 1960s and 1970s, becoming a symbol of that era's culture. Bell-bottoms, characterized by their widening shape from the knees down, were often made from denim and paired with various footwear, such as Chelsea boots and clogs. The style was notably popularized by celebrities like Sonny and Cher and was featured in songs like "Bell Bottom Blues" by Derek and the Dominos. To celebrate, individuals are encouraged to wear bell-bottoms, add them to their wardrobes, or host themed parties reminiscent of the 1960s and 1970s. Additionally, participants can share photos on social media using the hashtag #BellBottomsDay to promote the holiday.