Book-in-a-Day is a reading challenge where participants aim to read an entire book within a single day. This activity encourages readers to immerse themselves in a story, often leading to a deeper understanding and appreciation of the material. It can be done individually or as part of a group, fostering a sense of community among book lovers. Many people choose to participate in Book-in-a-Day events during National Reading Month or other literary celebrations. The challenge can involve various genres, allowing readers to explore new authors and styles while enjoying the thrill of completing a book in a short time frame.