Definitely not. 'One Day' is purely fictional. The author likely used their creativity and storytelling skills to come up with the plot and characters, rather than basing it on actual events or people.
One Day is not based on a true story. It's a work of fiction that explores various themes and scenarios that are made up by the writer to entertain and engage the readers.
Sure. There could be. Writers are often inspired by real - life events and might be able to create a novel in a day if they are highly motivated and the story is already well - formed in their minds. It might not be a long or complex novel, but it can be based on a true story.