Never again shall the time Operation of Clocks: Clocks for Europe are equipped with a receiver for the DCF77 signal, which in Mainflingen / Frankfurt is broadcast. Three independently operating atomic clocks each generate a time signal. After comparing the time signals broadcast by each of the master clock signal on the long wave of Mainflingen from within a radius of up to 2000 KM. This time information is generated by the Physikalisch-Technische Bundesanstalt in Braunschweig and broadcast on the telecom towers.