Not in agreement here - time is always positive. I suggest time is a process and not a dimension. Negative time, where applied is about direction i.e. a positive process in the opposite direction. NB all in 4D SPATIAL dimensional space. The 3D spatial awareness that we have - the Macro universe - is movement in the 4th spatial dimension. This movement is the thing we call time.
The point is that movement is positive. I suggest that UNmovement is difficult to conceive without adding another spatial dimension. Our reality seems to be four-dimensional. How compatible with GR is this idea (GR being a well-proven framework)?