Introducing The Lange 1 Perpetual Calendar In Platinum
The Lange 1 Perpetual Calendar’s movement is one of the most ingenious Lange has ever made.
The Lange 1 Perpetual Calendar is not the first perpetual calendar to be built around the iconic Lange 1 design. It was launched in 2020, but was preceded, all the way back in 2012, by the Lange 1 Perpetual Calendar Tourbillon, an automatic tourbillon wristwatch with perpetual calendar. The original models from 2020 were in pink gold with a dark grey dial, and in white gold, with a pink gold dial. This year, Lange has introduced a new model in platinum, with a black dial. It’s an extremely handsome watch – I have always thought that the mass, heft, and general sense of solidity you get from platinum, as well as its rather frosty hauteur, make it an ideal metal for Lange & Söhne watches (the first version of the Saxonia family Datograph, in platinum, remains my personal favorite) and in addition to expanding the range, the new platinum model gives us a chance to look back at one of the cleverest implementations of a perpetual calendar in the world.
A perpetual calendar is one which takes into account all of the months with both 30 and 31 days, as well as the 28 day length of February, switching the date automatically and correctly at the end of each month.
The classic perpetual calendar mechanism, as seen above in the perpetual calendar plate from Lange’s grand complication pocket watch from 1902, keeps track of the length of each month via a program disk with 48 steps in it, seen in the picture at 12:00. This is with variations, pretty much the standard method for implementing a perpetual calendar in a wristwatch.
The depth of each step corresponds to the length of any given month, and the deeper the step, the further the beak of the lever (just to the left of the cam) can drop. The further it drops, the sooner the lever switches the date indication (at 3:00). If you look closely, you’ll see four steps deeper than the others – these correspond to the month of February over a four year cycle. The slightly less shallow February step, at about 6:30 on the program disk, allows the date of February to advance to the 29th in a leap year, before switching the date. The above mechanism’s also an instantaneous perpetual calendar. You can make a perpetual calendar with just 12 steps in the cam, as well, by installing a smaller cam on it for the four months of February in a leap year cycle, which rotates once per year to bring a step of the correct depth into position.
The Challenges Of A Perpetual Calendar Lange 1
The idea for a perpetual calendar built around a Lange 1 design goes all the way back to the rebirth of the company under Walter Lange and Günter Blümlein, but making one proved very difficult technically and it wasn’t until 2012 that Lange was able to introduce a solution to the problem. There were several significant technical challenges, including the question of controlling the switching of the big date display at the end of each month, and how to display the month and leap year without disrupting the classic Lange 1 design.
In order to display the month, Lange hit on the idea of showing the month via a rotating ring around the periphery of the dial. The big date display and subdial for the hours and minutes would therefore be able to maintain their relative relationship as found in the original Lange 1 (although the subdial for the time would shift to the right hand side of the dial and the big date display to the left) and, instead of the auf/ab power reserve indicator on the Lange 1, there would be a hand indicating the day of the week. Lange was also able to incorporate its high precision moonphase display, which is correct to one day’s error in 122.6 years. Both the Lange 1 Perpetual Tourbillon, and the Lange 1 Perpetual, have the same perpetual calendar mechanism, although the Lange 1 Perpetual’s movement is built on the Lange Daymatic caliber L021.1.
The big “eureka” moment for Lange was the idea of doing away with a conventional 12 or 48 step program disk and instead, using the month ring itself as the cam for switching all the date indications. The depth of the inner edge of the month ring varies according to the month, and the tip of the feeler lever that senses the depth of the edge can be seen above, next to the month of October. The Leap Year indication, just above the month of December, is switched once per year by the rectangular tooth on the month ring, just above the transition between December and January (the month ring rotates anticlockwise).
The second big problem was that Lange’s Anthony de Haas (who has been Lange’s director of product development since 2004) wanted all the indications to switch simultaneously at midnight. At midnight on January 31st, that would mean instantly switching the ones disk and tens disk of the big date display, as well as the month, leap year, and day of the week. Getting all indications to jump instantly as well as simultaneously took some doing, and Lange eventually settled on the use of two snail cams which allowed energy to be gradually stored over time, in order to jump all of the indications at once. Lange has published an excellent animation to get across just how all of these systems work together.
The Lange 1 Perpetual Calendar is also full of wonderful little details, as you might expect and one of my favorites is the star field behind the two moonphase disks. The star field is printed on its own disk, which rotates once per day – during daylight hours, the background behind the Moon is deep blue.
At night, though, the stars come out.
All of this beauty and complexity fits into a relatively small case (and as you can see from the video, there is very little room left over inside the watch). The watch overall is 41.9mm x 12.9mm, and the movement is 35.8mm x 8.8mm – which, considering this is a self-winding, full-rotor, instantaneous perpetual calendar with moonphase, is remarkably compact.
If you are looking for a technically advanced, visually striking, and very substantial-feeling perpetual calendar, the Lange 1 Perpetual Calendar in platinum is very hard to beat. It’s all the more interesting in that as is usually the case with Lange, there are no high-tech materials solutions inside – just 621 components, including Lange’s signature German silver (maillechort) plates and bridges. Like its predecessors, it is a watch of enormous dignity and if it says anything about its wearer, it’s that they are a person who has unshakeable confidence in their own, mature, well-developed good taste.
The Lange 1 Perpetual Calendar in platinum: case, platinum, 41.9mm x 12.1mm, sapphire crystals front and back. Movement, Lange caliber L021.3, full rotor automatic with 21k gold rotor fitted with peripheral platinum weight, with unidirectional winding. Plates and bridges in untreated German silver (maillechort). Instantaneous perpetual calendar, with big date, high precision moonphase with day/night indicator, day of the week, month, and leap year indications; 621 components running in 63 jewels at 21,600 vph; movement adjusted to five positions. Power reserve, 50 hours. Price on request.