In recent years, there has been a number of incidents against the security of the location services. Jamming and spoofing attacks are intensively studied to find effective detection and mitigation techniques to provide secure signaling. However, the effects of the number of spoofing signals are not completely understood yet. In this paper, we focus on the distance-based consequences of GPS time-spoofing attacks. We analyze the impacts of falsification of GPS time stamp and signal travel time, where there are still authenticated signals in addition to the spoofing signals. The results show that the spoofer may be very effective even if it only generates a copy of one GPS signal by creating its attack signal.