An electronic timepiece is equipped with a frequency division ratio adjustment circuit controlled by switch means, for producing a running rate correction signal that is aperiodically added in frequency to the output of a standard frequency oscillator, to correct the running rate of the timepiece, and is provided with externally controlled gate means for inhibiting this aperiodic frequency addition, so that the actual frequency of the standard frequency oscillator may be measured by means such as an external monitoring device which detects a display drive or modulation signal frequency through electrostatic or electromagnetic coupling to the timepiece display.