Towel Day is celebrated annually on May 25th in honor of the late author Douglas Adams, best known for his science fiction series, The Hitchhiker's Guide to the Galaxy. The day encourages fans to carry a towel, a key item in the series, as a symbol of their appreciation for Adams' work and his influence on literature and culture. The tradition began in 2001, shortly after Adams' passing, and has since grown into a global event. Fans participate by displaying towels in various ways, attending themed gatherings, and sharing their love for Adams' writing, fostering a sense of community among readers and enthusiasts.