Convention in the Definition of Geometry of Space-Time
Keywords: simultaneity, geometry relativity, transformation
A hundred years ago, Poincar? pointed out that relativistic mechanics can be described within different geometries of space-time. This paper assumes the signal method of clock synchronization in pseudo-Euclidean, Euclidean and Galilean geometries, and obtains transformations of coordinates and time for these geometries under general nonstandard clock synchronization.