Time line

A short but vivid dream last night of floating along a thin line. I looked down and could see another fuzzier line which had hours marked on it, although not very clearly. I was aware that I could float downwards to, say 7am, and then I would awaken at that time. I was in a slightly lucid dreaming state. Also aware of a friend nearby watching me and perhaps a bit concerned.
Wondering now of course if it was uni-directional, could I reverse? Could I speed ahead? Maybe not possible or allowed.