The Reason
The Hijri QP calendar wristwatch is based on technology Parmigiani Fleurier originally developed for a table clock launched in 2011, it was motivated by the restoration of an early pocket watch featuring an Arabic calendar.
Functions
Hours, minutes, seconds, Hijri perpetual calendar with moon phases.
Explanation of the Hijri calendar (partly provided by Parmigiani)
The Hijri lunar calendar is based on the cycles of the moon and consists of twelve months of 29 or 30 days depending on the moon phase and is used to pinpoint the days for Islamic holidays.
In contrast to the Gregorian calendar based on the solar calendar, the months of the lunar calendar change annually by a difference of -10 to -12 days.
The name and lengths of the months are in Arabic calligraphy, as well as the abundant and the common years. (The Hijri lunar cycle is 30 years. It consists of 19 common years with 354 days and 11 abundant years with 355 days.).
Technical Specifications
Calibre: PF009, perpetual calendar with automatic movement. Power reserve: Up to 48 hours. Frequency: 28’800 Vph (4 Hz). Total dimensions of movement and module: Ø 33.30 mm, thickness: 5.700 mm. Decoration: Hand-beveled, and decorated bridges with Côtes de Genève/Geneva stripes. Oscillating weight: Platinum – “Grain d’Orge” guilloché.
The case is made from polished platinum. Dimensions: Ø 44.50 mm in diameter, thickness: 14.09 mm. Glass: anti-reflective sapphires. Water resistance: 30 meters.
The case back is held in place by 4 screws. The additional 4 screws sitting in the shoulders traverse the case and hold the bezel in position.
In the two images below in the recessed circular zones, are lazer engraved images of, a set of scales and the head of a Saint Bernard dog made by a Swiss Assay office, proving the validity and origin of the material and place of origin of the case.
The tool shown below is the screwdriver made to loosen, and tighten the 8 inox steel case screws. The screws can not be made in platinum to avoid the screws and case fusing together.
The first view of the movement with the case back removed.
With the case back removed the inner case construction is viewed. A skeletonised ring houses the calibre, through which, the QP module that is fixed onto the calibre can be partially viewed.
The bezel loosened from the case.
The six, polished steel, and rhodium plated hands removed from the movement.
The hands removed and the movement and dial still in place, in the case. The case itself can often be the most effective movement holder for the initial stages of dismantling the watch.
The right subsidiary dial translated.
The movement removed from the case.
Recto-verso of the case showing the paddles that activate the QP module correctors.
The slate grey dial removed from the movement.
Full view of the unusual QP mechanism unusual both in technical and aesthetic executions.
The central bridges follow the shape of the climbing and descending crescent moons.
The moon phases disc sky is made in aventurine.
Inclined view showing the bombé moons set into the aventurine.
The Rub el Hizb, an Islamic symbol represented by two overlapping squares forms the shape of one of the bridges. In Arabic, Rubʻ means "one fourth, quarter", while Hizb means a group or party.
The moon phase disc removed.
The crescent moon and Rub el Hizb bridges removed.
The engraving on the cam below represent the abundant years aligned to the triangular shaped teeth. The years that have one day extra in the last month of the year.
The snail shaped cam is associated with the months and turns once every Islamic year moving the wheel that represent the 30 year cycle, increments of 1/30th.
The month assembly dismantled, the disc to the right acts as a spacer preventing the levers above and below from touching each other. The decoration on the disc is purely aesthetic.
Below the large lever that meshes with the white/peach coloured indicator, showing the abundant and common months. Those with 30 or 29 days. (The high section steps on the right hand cam cause the index to be visibly peach through the dial and show abundant months).
The abundant(30day)/common(29day) indicator piece, meshing with its operating lever.
A collection of the detent styled operating levers.
Calibre PF009
A perpetual calendar module with automatic movement. The power reserve lasts up to a duration of 48 hours. The frequency of the balance vibrates at 28’800 Vph (4 Hz). Total dimensions of movement and module together Ø 33.30 mm in diameter, thickness 5.700 mm. Decoration, hand-beveled, and decorated bridges with Geneva stripes. Oscillating weight made in platinum – “Grain d’Orge” guilloché.
Profile view of the movement with the module removed. The extended canon pinion and hour wheel drive the calendar mechanism.
The movement with the module removed.
The rotor weight removed from the movement, revealing the full form of the bridges.
Oscillating weight made in platinum – with “Grain d’Orge” guilloché (barley grain form, engine turning).
The polished angling on the bridges is executed manually.
The balance removed revealing the escapement.
The free-sprung balance (no index/raquet to alter the effective length of the balance spring) regulated by adjusting the position of the 4 maslots on the balance wheel.
The small hook shaped finger piece when pushed releases the click allowing the mainspring to run down, prior to dismantling the movement.
The Swiss anchor and its bridge removed from the movement.
The train bridge removed.
The barrel bridge removed showing the two barrels with the full gear train left in place.
Underside of the barrel bridge showing the automatic gear train and winding mechanism.
The full gear train including both barrels.
The main-plate with the majority of components removed.
Summary
The Hijri perpetual calendar is unique to “wrist” watchmaking, until this point in time 2020. The calendar mechanism adopts principles of cams with various depths affecting the lengths of months. This approach is classical for watchmaking but has never been executed in this particular construction before. The detent levers assure the watch has numerous safety elements throughout, protecting the mechanism when the watch is either programmed manually using the correctors, or wound backwards during the natural change of the calendar.
There is a congruency of design of the Hijri calendar concept from the dial through to the perpetual calendar mechanism. The function of the calendar links to the Islamic Lunar calendar. The dial text is in Arabic and the form of the calendar bridges hidden by the dial, are heavily linked with the Islamic culture.
Generally this congruency of design is uncommon in watchmaking, with a cultural distinction influencing mechanical construction and movement design, beyond decoration alone.
To learn more www.parmigiani.com