Are there any famous October dates in science fiction?

There could be an October date in a science - fiction series where a major battle between different factions (maybe humans vs. mutants or robots) takes place. This date then becomes part of the lore of that fictional universe and is remembered by the characters in later installments as a turning point in their struggle.

In some science - fiction novels, an October date might be when a particular alien race makes first contact with Earth. This date then becomes a significant milestone in the story and is often referred to throughout the narrative. For example, in a book where the alien encounter changes the course of human history, the October date of the first contact is crucial.