Objectivity is the only attribute of time.  Backward or forward, dimensionally the change of time won't  effect reality. As the meaning of time is built upon the results that time leaves, the only evidence, or record of time, is incident.  The existing of those happened, happening, or going to happen, defines the dimension of time.

Our culture prefer to define objects with units and tools: rulers, measures, weights, decibel, watt, meter. They all share the same feature: unity and consistancy, which is the same mechanism under which watch is working.

Deconstruction and restructure of the mechanism stands for the destroy of time demension and reforming of new instance. In this situation the break of old mechanism and birth of new instance is achieved, which is also, that a time machine supposed to do.