A hand position detecting device stops optical detection of the respective rotational positions of seconds, center and hour hands when such detection is impossible. When it is determined that the respective positions of the hands have not been detected successively a predetermined number of times, the detection of the hand positions is stopped until a predetermined time, for example 5 minutes before 11 o'clock or 55 minutes past 10 o'clock. This prevents unnecessary repetition of detection of the hand positions and hence useless consumption of battery energy which would otherwise occur.