Until the Tokyo Olympics, world records were measured by officials with stopwatches, measured to the nearest tenth of a second. Although fully automatic timing was used in Tokyo, the times were given the appearance of manual timing. This was done by subtracting 0.05 seconds from the automatic time and rounding to the nearest tenth of a second, making Hayes' time of 10.06 seconds convert to 10.0 seconds, despite the fact that the officials with stopwatches had measured Hayes' time to be 9.9 seconds, and the average difference between manual and automatic times was typically 0.15 to 0.20 seconds. This unique method of determining the official time therefore denied Hayes the record of being the first to officially record 9.9 seconds for the 100 meters. The first official times of 9.9 seconds were recorded at the "Night of Speed" in 1968.