This Tortue XL Jour et Nuit is part of the Collection Privée Cartier Paris (CPCP), a collection of watches based on historic Cartier designs but equipped with modern mechanical movements. Its design is based on the first Tortue created by Louis Cartier in 1912 and was aimed mainly at the men’s market. The watches in the CPCP collection were available between 1998 and 2008, albeit in very limited numbers.

A hallmark of this collection was the fact that the movements were made by external agents. The watches in the CPCP line had a distinct dial aesthetic (all but one model, the Tank Cintrée). The dials were crafted in solid gold and featured a hand-turned guilloche pattern with the brand’s Rosette signature at the centre of the dial beneath the handset.

The present watch’s charm lies in the fact that a second time zone is indicated without the use of additional hands, but via an artfully-engraved day/night disc. During the day, a sun motif on the disc indicates the hours - the sun beam extending to the outer track denotes the hours. At night, a moon appears on the rotating disc to display the hour