Catchthesnitch said:This chapter also starts a pattern of important things happening on Harry's birthday and Halloween. Discussed further below in general septology clues, but Harry's birthday and Halloween in each of the books hold significance. In this one, Halloween is the day that Harry's parents were murdered. It is also in this book the day that Harry Ron and Hermione become friends through the shared trauma of defeating the troll. In this book, Harry learns he is a wizard on his birthday.
Finnegan said:Now, this narrative structure can be seen as being repetitive within the text - it happened once, when Lord Voldemort first fell from power on Halloween, 1981 (which is recounted mainly in the first book, The Philosopher's Stone, and in the fifth book, The Order of the Phoenix)