Bones: You, ah, you present the appearance of a man with a problem.
Spock: Your perception is correct, Doctor. In order to return us
to the exact moment we left the 23rd century, I have used our
journey back through time as a reference. Calculating the
co-efficient of elapsed time in relation to the acceleration curve.
Bones: Naturally. So what's your problem?
Spock: Accleration is no longer a constant.
Bones: Well then, you're just gonna have to take your best shot.
Spock: Best shot?
Bones: Yes, Spock, your best guess.
Spock: Guessing is not in my nature, Doctor.
Bones: Well....Nobody's perfect.