Here is the barest sketch of an idea. Remember when I was talking about temporal hex crawls? And remember the way I categorized post-apocalyptic settings? Well, one way to encounter post-apocalyptic settings is through time travel... Which leads me to wonder if the post-apoc nomenclature might be usable for time travel as well.
Time travel targets could definitely be sorted into Near, Far, and Remote, with Mid perhaps representing non-standard temporal states, like Hasted, Slowed, or Phasing In and Out. And speed applies to time travel as well: does the traveler experience Instant travel to another time, a fast transition, or a slow one?
The third axis of severity might even be applicable. Semi-Temporal time travel might indicate only a partial shift -- just the traveler's mind, perhaps. Or maybe we should use other modifiers for that and restrict "Semi" to bilocation in time.