Watchmakers people are extremely specific and precise, not only in their manipulations, but also in thoughts and especially in terms. It is all the more surprising that a watch that has indicators of numbers, days of the week, months and years and does not need to be corrected over the course of many years is called a perpetual calendar. These calendars can be called relatively eternal. First, they stop as soon as the energy in their barrels or accumulators runs out. Secondly, much more often ordinary simple models fail due to a complicated wheel drive. And finally, February 29, 2100 will never come, because Pope Gregory XIII simply canceled it and this leap year does not exist in the generally accepted Gregorian calendar.
However, watches with a truly perpetual calendar exist and were first released in the Soviet Union (Raketa and Vostok watches). And yes, they were created not by watchmakers, but by mathematicians and designers. The Japanese company Orient later only borrowed it from its generous Soviet colleagues, who did not object to this.
Who is the first in eternity?
Some watchmaking historians argue that the first prestige watchmaking complication was not a repeater, but a perpetual calendar. As proof, they cite the watch of the master François Pigeon from Clermont-Ferrand, kept in the world's largest watch museum, Patek Philippe. In addition to the hour hand, this model has an alarm clock, a moon phase indicator, and a manual perpetual calendar module with indicators of numbers, days of the week and months.
The clock is dated 1625. But most historians refuse to recognize the manually adjusted perpetual calendar as mechanical complication: if the module were connected to the wheel drive of the mechanism, then it would be a different matter. Therefore, the great British master Thomas Muge is considered the author of the first perpetual calendar. Around 1750, he created a watch with a perpetual calendar, the wheel drive of which automatically determined the months with 28, 29, 30 and 31 days.
The most perfect and functional perpetual calendar watch in the world was created by the house of Vacheron Constantin (pictured). The Reference 57260 has 57 functions and complications. This is a tourbillon, a split-chronograph with two retrograde seconds hands and an alarm clock, supplemented by four types of perpetual calendar at once: Jewish (based on the 19-year Meton cycle), business (which works according to the ISO 8601 standard), ordinary Gregorian and astronomical. The white gold case has a diameter of 98 mm and a height of 50,55 mm.
General deceleration
And yet, what is the module that watchmakers call a perpetual calendar? This is a system of additional wheels that are connected to the main wheel drive of the mechanism. And you need these extra wheels to slow down the rotation of the calendar indicators - be it discs or axles with arrows at the end. After all, if the minute hand makes 1 revolution in 60 minutes, the hour hand in half a day, then the number indicator rotates during a month with a frequency of steps per day, the month indicator makes 1 revolution per year, the disc with the leap year indicator turns around once every 4 years ...
Previously, the unfortunate craftsman had to manually calculate the diameter of the wheels and gears in order to set the correct pace for the calendar. And now you load the technical data of the original mechanism into a computer that is not even the most powerful one, and a smart machine will calculate everything in less than a minute, and even tell you where in the depths of the caliber it is better to place the calendar wheels.
In general, it is easy to produce calendars these days! All the more so if you have at your disposal a state-of-the-art, state-of-the-art manufacturing facility. So the watchmakers have already mastered more than a dozen types of calendar.
Gregorian pattern
Until recently, the so-called perpetual Gregorian calendar was considered the coolest and most prestigious, which does not need to be adjusted at all, since, among other things, it has a set of additional wheels, the so-called leap. And since it still rotates, the watchmakers attach a disk called the indicator of years to the axis of this wheel.
As a rule, it is divided into four sectors with the numbers "1", "2", "3" and the letter "L" or "B" (Leap or Bissextile). And only Jaeger-LeCoultre, IWC, Ulysse Nardin, Vacheron Constantin and Patek Philippe have the most prestigious four-digit disc years. This is cool, since calendars of this format require the development and calculation of indicators for centuries (first two digits) and decades (third digit).
Interestingly, perpetual calendars themselves (without any other additional complications) are rarely released today. Watchmakers often add them to the super-complex models of the top watchmaking class Grande Complication. Only the large antique watch houses Patek Philippe, Vacheron Constantin, Jaeger-LeCoultre and Audemars Piguet regularly pay tribute to the tradition.
The model Reverso a Triptyque, released in 2006 for the 75th anniversary of the Reverso collection, has the most complex design of all perpetual calendars with a tourbillon (pictured), an equation of time function, a perpetual and astronomical calendar, which has not two, but three dials (the third is located on the bottom of the frame and on it the indicators of the perpetual calendar are located). And all these dials are connected to each other, even when the container with the hour capsule separates from the bottom of the case.
Eternity is in the box
A watch with a perpetual calendar is an extremely whimsical thing that requires particularly careful storage. Since all indicators are connected to the main wheel gear of the mechanism, it is necessary to be extremely careful to correct their readings (for example, if the watch has not started and stopped for some time). Due to the fact that many owners are not so careful, some manufacturers jokingly (and, of course, strictly among themselves) call the perpetual calendars "DHL-watches". They say that very often they have to be sent to manufactories for repairs and new adjustments. Therefore, it is better to store them in special watch boxeswhich wind up the watch themselves, whether automatic or even manual.
Perspectives of eternity
The most relevant trend today is to make all calendar indicators work instantly at the same time and exactly at midnight. So far, only Patek Philippe and A. Lange & Sohne have succeeded. And also the development of religious and ethnic perpetual calendars: the Mayan calendar was created by De Bethune, the eastern lunar calendar - Blancpain, Muslim and Jewish - Konstantin Chaykin. However, he recently introduced the Mars Conqueor watch with a Martian calendar and opened a completely new promising direction in the creation of alien perpetual calendars.
Seiko Premier Kinetic Perpetual SNP 149P2 Is one of the best auto quartz perpetual calendars. The word Perpetual in the name hints not only that it is a perpetual calendar, but also that the 7D56 movement's batteries are powered by a pendulum in a watch, like an automatic watch. They feature amazing accuracy +/- 1 second per month. The 42,9 mm case is made of steel.
Seiko Premier Kinetic Perpetual SNP 146P1 - a similar model with a "big date" indicator, indicators of months and leap years at the 6 o'clock position and 24 o'clock at the 3 o'clock position. The watch is able to "fall asleep" for up to six months, and when it "wakes up", it automatically sets all indicators to the desired position. The case is coated with the renowned proprietary 10 micron rose gold plating, which does not wear out.
Model Citizen Eco Drive CB5860-35X with a chronograph and an alarm clock, it operates in a perpetual calendar mode, although it does not have indicators for months, days of the week and years. The exact time in different zones and the date for the E660 mechanism, which is powered by the energy of light, is prompted by the GPS satellite.
