The indication of the 37 time zones as proposed by Vacheron Constantin in its Patrimony Traditionnelle World Time is as complete as one could wish for. The display consists of three dials: a sapphire dial with a unique day/night shading; a metal dial with a "Lambert projector" type map; and a metal chapter ring. Beating at a frequency of 4 Hz (28,800 vibrations per hour) and endowed with a 40-hour power reserve, mechanical self-winding Calibre 2460WT drives displays of the hours, minutes, central seconds and World Time. It enables simultaneous read-off of the time in all regions of the world, along with the day/night indication provided by the central world map. All indications are adjusted via the crown, thus considerably simplifying the use of this highly technical watch. In light of these exclusive developments, a patent has been filed for the new Vacheron Constantin Calibre 2460WT bearing the prestigious Hallmark of Geneva.