In Undertale the year is 201X which means it takes place between 2010-2019, and in the case of the war between humans and monsters, it could not have been too long ago if monsters like Gerson and Asgore still remember the sun. Using this information we can conclude that the War of Monsters and Humans happened in the 1900s, but during a time that had something more important taking place so it would not be included in history, such as World War 2 or the Cold War. In this essay I will