A. Lange & Söhne Datograph Perpetual: Platinum, Diamonds, and Two Time Horizons

A flyback chronograph captures fleeting moments, while a perpetual calendar thinks in decades. A. Lange & Söhne has combined both in the Datograph Perpetual since 2006. To mark its 20th anniversary, the complication now comes in a particularly exquisite version: the case and five-row bracelet are crafted from 950 platinum, and diamonds add small points of light to the black dial. The edition is limited to 50 watches.

Platinum all the way to the bracelet

With a diameter of 41 millimeters and a height of 13.5 millimeters, the Datograph Perpetual retains its original proportions. The new look is created primarily by the solid metal bracelet: polished and matte surfaces alternate, and the beveled links on the sides catch the light. A folding clasp secures the five-row bracelet. The high specific gravity of platinum is likely just as much a part of the wearing experience as its understated, cool luster.

Eleven baguette-cut diamonds totaling approximately 0.13 carats mark the hours; at 12 o’clock, two stones are set side by side. The sub-dials, offset downward, create space above them for the large date display. The stones complement the watch’s austere architecture without detracting from its information density. The result is a timepiece with a striking material presence.

Flyback and Perpetual Calendar

The column wheel coordinates the chronograph’s shifting operations. Its precisely stepping minute counter ensures that the measured value remains clearly legible even as the minute changes. The flyback function allows you to reset a running measurement with the press of a button and immediately start a new one. The chronograph divides the second into fifths.

The perpetual calendar takes into account the varying lengths of the months and the leap year cycle. If left running continuously, it will not require manual correction until March 1, 2100. The moon phase display deviates by one day after 122.6 years. The quick-set pusher at 10 o’clock allows the calendar displays to be advanced simultaneously; additional correctors are available for individual displays.

The caliber remains the true focal point

Inside, the watch is powered by the well-known in-house caliber L952.1, a hand-wound movement operating at 2.5 hertz. Of its 556 individual components, 223 make up the calendar mechanism. Lange assembles the movement twice: after the initial assembly and adjustment, the parts are disassembled again, finished, and finally reassembled. Through the sapphire crystal case back, one can observe the column wheel, the long shift levers, and the spatially staggered chronograph mechanism.

The power reserve is 36 hours. A watch with a perpetual calendar, in particular, requires regular winding: The long calendar autonomy is a theoretical property of the mechanism and depends on the watch continuing to run. This is also where the difference lies compared to the current design: Technically, the edition remains true to the tried-and-true Datograph Perpetual, while the platinum bracelet and diamond hour markers significantly alter its appearance.