The first, known example of this method was an accident when the USS Enterprise - trying to break free from the gravity of the planet Psi 2000 - was sent three days back in time. Later the same ship was sent much farther back in time; when it was dragged into the gravity well of a black star. After that the Enterprise purposefully used the technique to conduct historical research in the 1960s. (TOS episodes: "The Naked Time", "Tomorrow is Yesterday" & "Assignment: Earth")