A method for detecting the beginning of the dips of the amplitudes in the output signal of a time signal receiver identifying the beginning of a second in the time signal. The output signal of the receiver for the time signals is sampled N-times per second. The sampled values are stored to respective cells of a memory field with N cells. In the memory field a mean signal curve for the time interval of one second is generated over a period of several seconds. A minimum valve and hence the beginning of the seconds in the time signal is determined from the mean signal curve valves in the memory cells.