Arguing the Concept of Relative Simultaneity

By applying Einstein's procedure to determine whether or not two spatially separated events occur at the same time, it is shown that simultaneity does not depend on the observer's reference frame, but the way how to recognize/assess simultaneity definitely does. Thus Einstein's claim of relative simultaneity, i.e. the frame-dependence of simultaneity, is simply unsubstantiated and, as also shown here, is in conflict with the relativity principle.