<p>The device has a wheel (40) carrying a needle arranged for moving with respect to a reading scale and for indicating the number of a week. A setting wheel (34) is cinematically connected to a going gear train of a watch and is arranged for periodically driving the wheel (40). The wheel (40) is driven by a pitch of six degrees per year, and a correcting mechanism acts mediately on the wheel (40) for bringing the wheel (40) to a initial row of a timer of a dial (12) at six degrees from the position of twelve o`clock of the dial during initial week of a year.</p>
