JAEGER-LECOULTRE REINTERPRETS THE MASTER ULTRA THIN PERPETUAL CALENDAR

Key Facts : 

• High-performing Calibre 868 extends the power reserve to 70 hours
• A sophisticated aesthetic update to the case and dials
• A new model in pink gold with a midnight blue gradient dial*

Jaeger-LeCoultre conceived the Master Ultra Thin collection as the quintessential dress watch for the modern aesthete, harnessing the Maison’s long history of mastering thin calibres and epitomising its philosophy of uniting mechanical virtuosity with timeless beauty. In 2024, the collection has been refreshed and includes a new interpretation of the Master Ultra Thin Perpetual Calendar, featuring a subtly modernised case and dial design, as well as a significantly increased power reserve. Four variations are offered, including a new model with a gradient midnight blue sunray dial*.

Precise and Perpetual – Resolving the Anomaly of Time

The reason for the complexity of our calendar, with its leap years and different numbers of days in the months, lies in an anomaly between the way we measure civil time and the cycles of the celestial bodies on which those measurements are based. Our 365-day calendar year is almost 6 hours shorter than a solar year (the time it takes for the Sun to return to the same position in the sky, completing a full cycle of seasons), which lasts approximately 365.2425 days.

Consequently, for watchmakers, a perpetual calendar is among the most challenging complications to master; a miniature mechanical computer, it must automatically adjust for months of different lengths and for leap years. Unlike a simple date display, which must be adjusted at the end of every month that doesn’t have 31 days, a perpetual calendar will not need any manual correction until 2100, which is a non-leap-year centenary. On centenary years that are also leap years it needs no adjustment.

Calibre 868, which powers the 2024 Master Ultra Thin Perpetual Calendar, was designed, produced and assembled in-house at Jaeger-LeCoultre; it evolved from the well-proven perpetual calendar movement launched by the Manufacture in 2013. In line with the Manufacture’s constant drive for technical innovation, the latest-generation Calibre 868 features a new escapement and pallets – reconstructed in a slightly modified shape, they minimise friction and thus consume less energy – and offers a robust power reserve of 70 hours. The long power reserve is particularly appreciated in a calibre with such complex indications and allows the wearer to set the watch aside for an entire weekend and wear it again on Monday without needing to correct any indications. When required, correction is done simply, via a single corrector set in the side of the case.

A Sophisticated Update for the Perpetual Dress Watch

While the size of the case remains the same as the original Master Ultra Thin Perpetual calendar – retaining the elegant 39mm diameter and 9.2 mm thickness – its design has been subtly modernised, with revised proportions and slimmer, more elongated lugs that make it even more comfortable on wrists of all sizes.

The dial design has also been modified, while retaining all the symmetry and balance of the earlier layout. Refined sub-dials highlight the indications, making them even more legible than before; the starry sky of the moon phase display is more intricate; the applied hour markers have been elongated; and each facet of the Dauphine hands has a different finish – polished and satin. Taken individually, each change is so subtle as to be hardly discernible to the casual observer, yet they combine to create a more cohesive and timelessly elegant design – underlining the importance that Jaeger-LeCoultre attaches to precision in aesthetics as well as mechanics. Just above the hands at the centre of the dial, a small security zone indicator shows red to warn the user not to adjust the time or calendar indications at a time when it could damage the delicate mechanism.

Four variations are offered, including a model with a new gradient midnight blue dial that contrasts dramatically its pink gold case*. The azure finish of the sub-dials (ultra-fine engraving in perfectly regular, concentric circles) stands out against the sunray-brushing of the main dial, creating a beautiful play of light*. In addition, two pink gold models are presented with classical eggshell dials – one with diamonds set around the bezel, one without. A fourth variation is offered in steel with a sunray-brushed silver dial. The Master Ultra Thin Perpetual Calendar is presented on an alligator strap that can easily be interchanged according to the mood of the wearer.

True to La Grande Maison’s guiding philosophy of marrying tradition and modernity, the latest version of the Master Ultra Thin Perpetual Calendar presents one of horology’s great complications in a fresh and timelessly modern style.

TECHNICAL DETAILS

MASTER ULTRA THIN PERPETUAL CALENDAR

Case: pink gold; pink gold with diamond-set bezel (60 diamonds ~ 0.85 carats); steel

Dimensions: 39 mm x 9.2 mm

Calibre: automatic Jaeger-LeCoultre Calibre 868

Frequency: 28,800

Functions: hours, minutes, seconds, perpetual calendar (day, date, month, year) with red security zone, moon phases

Power reserve: 70 hours

Dial: gradient blue sunray*; eggshell; silver sunray

Strap: Black alligator (pink gold case with eggshell dial, steel case) / Blue alligator (pink gold case with midnight blue dial)*

Water resistance: 5 bar

References:

Q114258J – pink gold with midnight blue dial*

Q1142510 – pink gold with eggshell dial

Q1142501 – pink gold with diamonds and eggshell dial

Q114842J – steel with silver sunrayed dial

* The new pink gold model with a midnight blue gradient dial will be presented in May 2024.