Method for measuring the mean frequency of a digital signal (S DP , S DI ) which is derived from a reference periodic signal (S PR ) generated by an oscillator forming an electronic time base of a timepiece , this timepiece comprising a movement incorporating a mechanism formed by a kinematic chain which is arranged between a motor device of the movement and an analogue time display device , this kinematic chain comprising or being kinematically linked to a continuous rotation electromagnetic transducer whose mean rotational speed is regulated by a regulation device , associated with the electronic time base, according to a nominal rotational speed, this regulation device being arranged to successively supply the electromagnetic transducer with regulation impulses (BP n ) to regulate the mean rotational speed thereof, these regulation impulses defining respectively same events (tf n ) which are synchronised on the rising edges or on the falling edges of said digital signal and which are detectable, by a measurement device without galvanic contact with the movement, at respective detection times having the same time phase-shift with said same events; the measurement method comprising the following steps: A) Measurement, without galvanic contact with the movement, of a plurality of successive time intervals (TI n ) each occurring between two detection times which are detected for two respective regulation impulses among said regulation impulses; B) Determination, for each time interval of the plurality of time intervals, of a corresponding whole number (M n (S DP ), M n (S DI )) which is equal to the rounded result (NR n (S DP ), NR n (S DI )), to the nearest integer, of the division of this time interval by the theoretical mean period (PT DP , PMT DI ) given by said digital signal; C) Summation of the whole numbers determined in step B) for the plurality of time intervals, to thus obtain a total number of periods of said digital signal; D) Summation of the measured time intervals of the plurality of time intervals, to thus obtain a total measurement duration (T Mes ) corresponding to said total number of periods; E) Calculation of the mean frequency of said digital signal by dividing the total number of periods by said total measurement duration. A) Measurement, without galvanic contact with the movement, of a plurality of successive time intervals (TI n ) each occurring between two detection times which are detected for two respective regulation impulses among said regulation impulses; B) Determination, for each time interval of the plurality of time intervals, of a corresponding whole number (M n (S DP ), M n (S DI )) which is equal to the rounded result (NR n (S DP ), NR n (S DI )), to the nearest integer, of the division of this time interval by the theoretical mean period (PT DP , PMT DI ) given by said digital signal; C) Summation of the whole numbers determined in step B) for the plurality of time intervals, to thus obtain a total number of periods of said digital signal; D) Summation of the measured time intervals of the plurality of time intervals, to thus obtain a total measurement duration (T Mes ) corresponding to said total number of periods; E) Calculation of the mean frequency of said digital signal by dividing the total number of periods by said total measurement duration. <EOS>