Calendar watches: more than just a date
Simple, complete, annual or perpetual calendars: watchmakers use different devices, more or less complex, to display calendar information. Let’s focus with Frank Sans C on four watches by Longines, Rolex, IWC, and Chopard.
Before we dive in, it is important to remember that “calendar” (Quantième in French) is the watchmaking term that designates the date. There are different degrees of complexity among the calendar watches.
After the simple calendar, the “complete” calendar adds the day and month into the date’s display. The watch must be winded at the end of the month since it doesn’t take into account the difference between months with 30 days and those with 31 days.
More complex, the annual calendar takes into account this difference. It only requires to be corrected once a year (hence its name) in February.
The perpetual calendar is the most sophisticated one since it takes into account the leap years. No need to adjust it until 2100. Indeed, 2100 will not be a leap year because of an anomaly in our Gregorian calendar.
Longines Master Collection Chronograph with complete calendar, the multi-instrument
The Master Collection combines exceptional pieces from Longines. Just like this reference in steel with blue dial, available with a 42 mm diameter (€ 3,180) or a 40 mm diameter (€ 2,980).
The watchmaker, that bears the famous winged hourglass as its logo, reveals a calendar watch with multiple mechanic subtleties. Indeed, not only does this watch display a chronograph function, it also comes with a 24 hours indicator and a moon phase. There are also lots of features on the dial, but it doesn’t hinder a perfect readability.
It is easy to spot the central date hand with a crescent moon on its end. Day and month appear on two separate apertures at 12 o’clock… on the 30 minutes counter. The moon phase is displayed on the 12 hours counter at 6 o’clock. At 9 o’clock there is the small seconds with a 24 hours indicator.
The transparent case back with sapphire crystal displays the automatic movement, decorated with Côtes de Genève.
ROLEX Sky-Dweller, an annual calendar for great travellers
The Sky-Dweller, equipped with an annual calendar, is one of the rare complication Rolex calendar watches. Indeed, the Manufacture has developed its own device. This exclusive mechanism doesn’t have a date indicator, but features the date (at 3 o’clock under the Cyclops lens) and the month… but where? On the twelve apertures around the circumference of the dial, the logo at 12 o’clock and the date aperture.
Presented on the Frank Sans C video in yellow Rolesor (€ 17,150), the Sky-Dweller also delivers a second time zone on the off-centre 24-hour disc. One of the assets of this watch is that it’s easy to use. It is equipped with a “Ring Command” bidirectional rotatable bezel that allows the wearer to select the function before setting it by turning the winding crown.
Just like any Rolex instrument, this model is also certified “Superlative Chronometer”. It means that it has a double certification: one by the Official Swiss Chronometer Control (COSC) and the other one by the Rolex Manufacture itself with specific final controls. The result: an outstanding performance (i.e. a -/+2 seconds accuracy!) and a 5-year international warranty.
Read our detailed data sheet on the Rolex-Sky Dweller in yellow Rolesor
IWC Pilot’s Watch Chronograph with a perpetual calendar, the pilot’s calendar watch
In the calendar watches universe, the perpetual calendar is undeniably one of the signature complications by the IWC Manufacture, as perfectly illustrated by the Perpetual Calendar Pilot’s Watch Chronograph in steel (€ 29,800). Indeed, this impressive 46,2 mm piece displays the day and the small seconds at 9 o’clock, the date and the power reserve indicator at 3 o’clock and the month at 6 o’clock.
That’s not all, folks! There is also the year display between 7 and 8 o’clock and a double moon phase mechanism (lunar cycle of both hemispheres at 12 o’clock). This complication is even more ingenuous because it only has to be adjusted every 577,5 years (!) just like the natural cycle of the night star.
It is also important to highlight the fact that the calibre features the Pellaton self-winding system, bearing a ceramic component and two barrels that ensure seven days of power reserve. To sum up, the movement is remarkable and visible through the case back.
Read our detailed data sheet on the IWC Perpetual Calendar Pilot’s Watch
CHOPARD L.U.C Perpetual T Edition Dubail, a unique piece
A big thanks to Maison Dubail that accepted to lend the pink gold Perpetual Calendar Tourbillon Chopard for the calendar watches video of Frank Sans C. This unique piece distinguishes itself by its exclusive dial, guilloché with a very visual and shining pattern. As part of the L.U.C Collection, this timepiece is the epitome of Swiss fine watchmaking. Not only is it certified by the COSC, it also bears the prestigious Poinçon de Genève.
Tourbillon with small seconds at 6 o’clock, big date at 12 o’clock, day and day/night indicator at 9 o’clock, months and leap years at 3 o’clock: the dial is perfectly balanced. The instrument even shows the remaining power reserve (8 days maximum) of its self-winding movement with a perfect finish. This information is present through the sapphire case on the back, with also a beautiful view on the calibre decorated with Côtes de Genève.
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