To provide a race timing system and the like that can appropriately time each individual competitor in a race while reducing unnecessary communication.
A radio tag receives the current time transmitted from a current time transmitter and sets it as current time to keep (S11). If receiving transmission prohibition time plus the current time (S12), the radio tag starts timer control until the transmission prohibition time passes (S13). If detecting an electromagnetic field (S14) and detecting a polar change point of the electromagnetic field (S15), the radio tag specifies the counted time as a measured time (S16). The radio tag then determines whether or not the transmission prohibition time has passed (S17) and, only if it has passed, transmits the specified measured time and the like to a measured time receiver (S18).
MIKI YASUTOSHI
FUKUDA KAZUHIRO
Takanori Mamoru