A perpetual calendar (“quantième perpétuel” in French) displays the exact date — along with the day, month, and often the moon-phase — by automatically taking into account the variable length of the months and leap-year cycle. Creating such a calendar is one of watchmaking’s most difficult feats, since its movement must have a mechanical “memory” of 1,461 days, or four years. The mechanism is usually based on a differential gear system from the hour wheel and includes several hundred components, cogs, gears, levers and rockers. A small toothed planet wheel connected to the month’s mechanism makes a complete rotation in four years. During the fourth year, this mechanism displays February 29 before jumping to March 1. Similarly to the moon moving around the earth, the planet wheel rotates on its own axis resting on a swivel wheel. A perpetual calendar should not require a manual date correction until March 1, of the centennial year 2100, which the Gregorian calendar rules will not be a leap year.
Unlike many other calendar watches, whose functions can be difficult to adjust, this watch also emphasizes ease of use. All corrections are made using the three-position crown, except for the quick correction of months, which uses a hidden corrector lever beneath the lug at 1 o’clock and does not require a separate tool. The months with 28, 29, 30 and 31 days are automatically taken into account, and leap years are indicated in the center of the dial, under the hour and minute hands. Years 1, 2 and 3 are in black type and year 4 (the leap year) is in red.
The movement, automatic caliber FPJ 1300.3, is manufactured in 18K rose gold, another hallmark of the F.P. Journe brand. It features the exclusive, off-center F.P. Journe rotor in 22K rose gold, which winds the movement in only one direction with an autoblocant (self-blocking) ball-bearing system. This system gives the watch an effective power reserve of 120 hours; the power reserve is indicated by a retrograde display on the dial at 9 o’clock.
The Quantième Perpétuel is available in platinum or in 18K rose gold, in 40-mm ($66,000 for rose gold, $69,000 for platinum) or 42-mm diameter. The dials are also in rose or white gold, and fixed by a steel circle with a silver chapter ring. F.P. Journe says that this new model essentially replaces the Octa Calendrier model in the collection, so owners of that watch may be pleased to learn that their timepiece becomes more collectible when the Octa Calendrier ceases production in 2013.
Technical characteristics:
Movement: Caliber FPJ 1300-3, automatic; diameter = 33 mm; thickness = 5.20 mm; frequency = 21,600 vph; 340 parts including 37 jewels; linear escapement with 15 teeth; chronometric balance with inertia weight; anachron free-sprung flat balance spring; 160-hour power reserve; circular graining on 18k gold baseplate; circular côtes de Genève on 18k gold bridges
Functions: hours, minutes, perpetual calendar with instantaneous jump, simultaneous correction of date and day via crown, correction of month and leap year via hidden, secure corrector
Case and strap: Rose gold or platinum case, 40-mm or 42-mm diameter; on black leather strap
Dial and hands: Rose gold or platinum dial, with silver chapter ring and steel mounting to affix the center of the dial; center-mounted hour and minute hands; leap-year indication by small central hand; two apertures at 12 o’clock for day and month, double aperture at 6 o’clock for large date; hand-type power reserve at 9 o’clock
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This must be the easiest to read perpetual, by me much preffered to the hands pointing to days and dates which takes longer to adjust your eyes to.
There are other perpetuals with small windows but in my opinion the Octa perpetual is a very beautiful and most practical of all the grand complications (minute repeaters, tourbillons or lesser complications as chronograph…) – the moment I will be able to afford the platinum one (rather than spend on a good car), I am going to have it!
how much
$66,000 for rose gold, $69,000 for platinum