ith the off-centre displays and peripheral month ring, the Lange 1 Perpetual Calendar endows a sophisticated complication with a unique face. Launched in April 2021, the white-gold model version with a solid pink-gold dial, limited to 150 pieces, and the pink-gold version featuring a grey solid-silver dial, are now joined by a platinum model with a black dial. The dark background effectively highlights the moon-phase display with its integrated day/night indicator.

Centred exclusively on its eponymous complication, the Lange 1 Perpetual Calendar introduced two years ago, represents the highest standards in precision, design and originality, resulting in a singular appeal. The new model version, housed in a 950-platinum case and measuring 41.9 mm in diameter, is complemented with a black dial, thus enriching the watch family with a particularly refined colour combination. The month ring provides the framework for all the displays. The numerals of the outsize date and the leap year contrast well against the black background. All calendar indications switch instantaneously and therefore produce unambiguous readings at any given time. They can be advanced collectively or separately with correctors. Once set correctly, the mechanism is programmed to accurately display the turn of the month until 2100.

Designing a mechanism presents a challenge that the ambitious A. Lange & Söhne developers took on in 2001 with the Langematik Perpetual. Their objectives: seeking innovative technical solutions while assuring optimum legibility. In order to preserve the signature design of the Lange 1 watch family with its off-centre and non-overlapping displays, Langeʼs watchmakers opted for a completely new approach and developed a peripheral month ring that advances instantaneously at the end of each month. Premiered in 2012 with the launch of the Lange 1 Tourbillon Perpetual Calendar, the innovative mechanism replaces the traditional design where the month display is controlled by a 48-step cam.

“The commitment to tailor the complex mechanical requirements to the characteristic design of the Lange 1 presented our developers with constructive challenges, as the large peripheral ring has to be advanced instantaneously by 30 degrees from one month to the next. Throughout the month, energy is collected via a cam in order to provide the required power exactly on time, at midnight on the last day of the month,” explains Anthony de Haas, Director of Product Development. “Thanks to this design feature in the Lange 1 Perpetual Calendar, the watch familyʼs distinctive face is maintained. The timepiece is therefore also emblematic of our philosophy to continuously break new ground in the realm of precision watchmaking.”

Adding a day/night indicator to the moon-phase display is also typical of the manufactureʼs continued quest for precision. Constructed across two levels, it consists of a solid-gold celestial disc with graduated blue hues that rotates around its own axis once and 3 seconds ‒ with such precision that the display only needs to be corrected by one day during 24 hours. Against this backdrop, the white-gold moon performs its synodic orbit in 29 days, 12 hours, 44 minutes and 3 seconds ‒ with such precision that the display only needs to be corrected by one day after 122.6 years. First implemented in the Lange 1 Moon Phase in 2016, the indication depicts the earth’s companion moving across a bright-blue sky during the day and a dark-blue starry sky at night, thus indicating the diurnal and nocturnal hours respectively.

The high standards of artisanal perfection upheld by the Saxon manufacture immediately become apparent at a glance through the sapphire-crystal caseback of calibre L021.3 ‒ it is elaborately finished by hand and assembled twice. The technical features of the manufacture movement include a unidirectional winding rotor in 21-carat gold with a centrifugal mass in 950 platinum, a power reserve of 50 hours and a balance with eccentric poising weights that beats at a frequency of 21,600 semi-oscillations per hour. Lange-typical quality hallmarks such as plates and bridges made of untreated German silver decorated with Glashütte ribbing, five gold chatons held by blued-steel screws as well as the balance cock engraved free-hand, with the whiplash spring mounted above to regulate beat adjustments reflect the manufactureʼs lofty aspirations in every single detail.

TECHNICAL SPECIFICATIONS

Movement
Lange manufacture calibre L021.3, self-winding, crafted to the most exacting Lange quality standards, decorated and assembled by hand; precision-adjusted in five positions; plates and bridges made of untreated German silver; unidirectional winding rotor in 21-carat gold with centrifugal mass in 950 platinum; balance cock engraved by hand

No. of movement parts
621

No. of jewels
63

No. of screwed gold chatons
5

Escapement
Lever escapement

Oscillator
Shock-resistant balance with eccentric posing weights; balance spring manufactured in-house, frequency of 21,600 semi- oscillations per hour; precision beat adjustment mechanism with lateral setscrew and whiplash spring

Power reserve
50 hours when fully wound

Functions
Time indicated in hours, minutes and subsidiary seconds dial; perpetual calendar with instantaneously advancing displays for outsize date, day of week, month and leap year; moon-phase display with integrated day/night indicator

Operating elements
Crown for winding the watch and setting the time; correctors for switching all calendar displays or for individual switching of the month, day of week and moon phase

Case dimensions
Diameter: 41.9 millimetres; height: 12.1 millimetres

Movement dimensions
Diameter: 35.8 millimetres; height: 8.8 millimetres

Crystal and transparent casebook
Sapphire crystal (Mohs hardness 9)

Case
950 platinum

Dial
Solid silver, black

Hands
Rhodiumed gold

Strap
Hand-stitched leather, black

Buckle
Prong buckle in 950 platinum