A master at creating highly complicated record-breaking watches, Vacheron Constantin this year unveils the fruit of 11 years of research and development on the part of three master watchmakers in its Ateliers Les Cabinotiers department. The Berkley Grand Complication two-sided pocket watch boasts the world’s first Chinese Perpetual Calendar — accurate to the year 2200. It has been deemed the most complicated watch in the world; the movement, Caliber 3752, is equipped with 2,877 hand-finished, hand-assembled parts. In fact, it took one watchmaker a full year to assemble it. Commissioned by American billionaire William Berkley, the watch boasts 63 complications, including two different perpetual calendars. The Chinese Perpetual Calendar was thought to be too complex to put into a watch due to its lunisolar system, different numbers of days per month, and differing start and end dates of the Chinese New Year, among other factors. But Vacheron Constantin’s masters accomplished the feat. The watch also features the Gregorian Perpetual Calendar, chronograph, triple-axis tourbillon, world time and second time-zone indication.