A. Lange & Söhne Showcases a Classic High Complication in New Lange 1 Perpetual Calendar

Twenty years ago, A. Lange & Söhne produced its very first wristwatch with a perpetual calendar, the Langematik Perpetual. In the years since, the Saxon manufacture has installed the prestigious complication in seven other models, mostly in combination with a chronograph, tourbillon, or both. Unveiled today at watches & Wonders, in a move many would say is overdue, Lange's distinctive take on the perpetual calendar finally gets a solo showcase in the famous off-center architecture of the flagship Lange 1 series. Here's what you need to know about the new Lange 1 Perpetual Calendar.

The watch adopts the new approach taken to perpetual calendar design that Lange established in 2012 with the Lange 1 Tourbillon Perpetual Calendar, i.e., the use of a peripheral month-indicator ring that advances every month rather than the 48-step cam control commonly used for this function. Such a system is more challenging from a technical standpoint, as advancing the ring at the end of each month requires substantially more power than the traditional mechanism. Along with this ring-shaped display, the dial features a retrograde day-of-the-week display at 9 o'clock, a leap-year indication at 6 o'clock, and the hallmark Lange "outsize" date display at 10 o'clock, in addition to the time display on the large, off-center subdial at 3 o'clock. All the calendar displays can be advanced with correctors, and once they are set, the watch should not need re-setting until the year 2100.

Complementing and enhancing the perpetual calendar functions is the sophisticated and ornate moon-phase display at 7 o'clock, which also includes a day-night indicator. The solid gold moon-phase disk, with its star-dappled, gradating blue background, makes a complete rotation on its own axis once every 24 hours, while the moon itself makes its own synodic orbit every 29 days, 12 hours, 44 minutes and three seconds, precisely matching the actual moon's phases. This display, which debuted in 2016's Lange 1 Moon Phase model, will require adjustment by only one day every 122.6 years.

Measuring 41.9 mm in diameter and 12.1 mm thick, the case of the Lange 1 Perpetual Calendar is offered in either 18k rose gold, framing a gray dial of solid silver, or in an 18k white gold case with a solid rose-gold dial, the latter a limited edition of 150 pieces. Inside both precious-metal cases is A. Lange & Sohne's 67th(!) in-house caliber, the automatic L021.3, which is based on the L021.1 at the heart of the Lange 1 Daymatic. Its unidirectional rotor is made of 22k gold with a centrifugal mass in platinum. On display behind a sapphire exhibition caseback, the movement holds a 50-hour power reserve and boasts the expected array of distinctly Saxon haute horlogerie embellishments, such as Glashütte ribbing on the plates and bridges made of untreated German silver, thermally blued screws, and hand engraving on the balance cock.

The A. Lange & Söhne Lange 1 Perpetual Calendar will retail for $104,500 in its rose-gold version; the 150-piece limited edition in white gold (below) is priced at $116,000. Both come on brown alligator leather straps (a rich, reddish brown for the rose-gold case, a darker brown for the white gold) with prong buckles in the same precious metal as the case.