You are referring to the novel _1984_ by George Orwell. In _1984_, there were three large countries that existed—Oceana, Eurasia, and Eastasia. Airstrip One is the name that was given to what we know as Britain. Another thing given to Britain as Airstrip One is the use of military time. This can be assumed to be done in order to lend to the tone/setting within the novel. What military time use does within the novel is contribute to the police state air/vibe that exists for the protagonist Winston Smith.