In the early 1980s, IWC's chief watchmaker Kurt Klaus succeeded in translating the Gregorian calendar and its many irregularities into a mechanical programme for a wristwatch. His ingenious perpetual calendar, which was first used in the Da Vinci Perpetual Calendar in 1985, consists of only around 80 individual parts and displays the date, the day of the week, the month, the year in four digits and the moon phase. The intelligent mechanical programme automatically recognises the different lengths of the months and adds a leap day every four years at the end of February. The moon phase display is so precise that it only deviates from the actual orbit of the earth's satellite by one day after 577.5 years. All displays are perfectly synchronised with each other and can be easily adjusted using the crown.
 
The brand - which is also known as the watchmakers’ watchmaker, because of there highly specialization in complex movements and delivery to other swiss manufacturers - delivers old-world charm, watchmaking refinement and effortless elegance with just the right touch of contemporary style with the Jaeger-LeCoultre Master Ultra Thin Perpetual Calendar. Although Jaeger-LeCoultre is best known for its Reverso, this Master Ultra Thin Perpetual Calendar thus proves that the brand's technical heritage lives on. Measuring 39 mm in width, this stainless steel calendar timepiece is the perfect backdrop for the irresistible mechanical charm of this complicated watch. With only 9.2mm of height, JLC still somehow manages to include a total of 336 parts in the movement.