1984 is the year in question—the year of things sucking completely. Orwell originally envisioned the title to be "The Last Man in Europe." Doesn't exactly get you sweating with anticipation, does it?
Fortunately for us, Orwell’s editor said something along the lines of "yawn" and changed it to the far more sensational and perspiration-inducing 1984, as we know it today. But why not 1985? Or even 1983?
Well, quite honestly, no one really knows. But there has been a lot of speculation (read: made-up stuff) to explain. It might be that Orwell, in 1948, thought a simple, two-digit switcheroo would do the trick (most scholars are partial to this one). Then again, maybe he wanted to honor his late wife, poet Eileen Maud O'Shaughnessy, and named the book after her poem, "End of the Century, 1984".
There are many other conspiracy theories involving other authors and texts, but those are mostly the result some bored book geek sitting around and finding every possible instance that the year 1984 is used in literature. So for now, your guess is as good as ours.