As deserasmus said, there's no equivalent short neutral translation. English has the strange ability to create short, neutral, straight-to-the-point, direct phrases. There's nothing "sentence-like" in it. In Hungary we often say English sentences are just words thrown one after the other. It's an exaggeration, but that's how it feels. Imperative sentences are more "personal" in Hungarian, they have an ending expressing that "you" have to do it. It's not just the bare word as in English (like simply "complete").
One way is "A cél 1000 nap absztinencia." = "The goal is 1000 days of abstinence".
But you could also say: "Legyél 1000 napig absztinens!" = "Be abstinent for 1000 days".
Maybe the best one is simply "1000 nap absztinencia" (1000 days of abstinence)