It would definitely make for good sci-fi. I've thought similar
  things about someone who could walk back and forth through time
  as we do in space. They'd flit in and out of existence from our
  perspective and unless they were keeping EXACT PACE with us,
  it's unlikely we could make sense of what they were up to.
  They'd have to see (sense, not necessarily vision) our speed in
  time to get in our plane properly. I also have thought of a
  second time axis and what that would be like to experience. I do
  think Science is rather locked into the arrow-view of time
  generally. I suppose it must be in order to function properly.
  Cause and effect as it stands is kinda needed. A fiction of time
  is required that we _already_ know is a fiction: an arbitrary
  time standard, encapsulated now in the goings on of the electron
  shells of two cesium atoms if I remember correctly but THEIR
  calibrations based upon a mathematically imperfect understanding
  of the motions of the moon and sun and stars, just like days of
  old. The Islamic calendar has it right in that regard, by
  utilizing observation, although it gets rather complicated even
  there. I just woke up but I'm always ready for my mind to go
  into Time things. Always fascinated by it.