Parmigiani Fleurier gives you the Moon – and Sun

Watchmaker's latest cultural-calendar project puts a face to Chinese lunisolar system

Tonda PF Annual Calendar in rose gold.

With its ability to follow lunar cycles, the Tonda Hijri Perpetual Calendar earned Parmigiani Fleurier the Innovation Prize at the Grand Prix D'Horlogerie de Genève 2020.

The platinum wristwatch was the second in a trilogy, which started with the Gregorian Annual Calendar and is now complete with the new Tonda PF Xiali Calendar based on the Chinese lunisolar system that dates back to the Shang dynasty (1570-1045 BC).

Parmigiani Fleurier's third cultural-calendar project features hybrid timekeeping, which takes into account the Moon's synodic orbit around the Earth and the Earth's orbit around the Sun.

"Calendars are a radiography of civilisations. I think of the Maya and the Toltec cultures, which had calendars that were very similar to the Chinese lunisolar calendar," said master watchmaker Michel Parmigiani, who founded his eponymous brand in 1996.

In the early 1990s, Parmigiani restored an antique pocket watch with an Islamic calendar. This know-how was later applied to create a table clock in 2011, followed by the award-winning Tonda Hijri Perpetual Calendar.

"Calendars were born from a need to understand nature's seasons, to plan the times for sowing seeds and harvesting crops, to anticipate and manage the winter's cold and the summer's heat. The calendar exists because we need to anticipate the phenomena of nature's nurturing," he noted.

Tonda PF Xiali Calendar with the complex information condensed on the dial in Imperial Red.

Besides agriculture, the calendar allows organising the rhythm of social and religious life, such as the beginning of the new year.

Launched earlier this month to welcome the Year of the Rabbit, the Tonda PF Xiali Calendar is housed in a steel case with a knurled bezel in 950 platinum.

In auspicious Imperial Red, the multi-level barley-grain guilloché dial sets the stage for the lunisolar calendar with its complex information in classical Chinese characters.

The external subdial is dedicated to 24 solar terms, such as equinoxes, solstices and weather changes, which were important in ancient China for optimising agricultural yield. The solar terms correspond to 24 divisions of 15° of the Sun's path along the ecliptic, or the path of the Sun as seen from the Earth.

Unlike the Gregorian calendar, which names the months and numbers the years, the traditional Chinese calendar names the lunar years and numbers the months.

The mechanically-programmed complication covers a period of 12 years via a cam system.

Because the 12 lunar months do not add up to a full solar year, the synchronisation requires adding an intercalary month, with the 13th month occurring approximately every three years.

The system operates under a 60-year cycle, determined by two series of the 10 Heavenly Stems and 12 Earthly branches. Each stem is paired with a branch giving the 60 combinations to form the cycle.

The Earthly Branches also correspond to the 12 zodiac animals, which designate the years of the sexagesimal cycle.

The 12 zodiac animal signs along with five elements -- Wood, Fire, Earth, Metal and Water -- are incorporated into the sophisticated system, not to mention corresponding yin or yang.

Parmigiani Fleurier neatly captures the various information on the red dial of the Tonda PF Xiali Calendar.

Opposing a moon phase display, the subdial at 12 o'clock has three levels to indicate the names of the year, the zodiac animals and elements as well as yin or yang in alternating colours.

The numbering of days is shown on the subdial at 3 o'clock, with an aperture for the length of the current month. The month numbers appear on another subdial at 9 o'clock, with a window to show the leap month.

The fascinating displays run in tandem thanks to Calibre PF008 with a skeletonised oscillating weight in 18k pink gold.

Tonda Hijri Perpetual Calendar, winner of the GPHG 2020 Innovation Prize.

As the traditional Chinese calendar is not cyclical, the mechanically programmed complication covers a period of 12 years via a cam system. At the end of these 12 years, the watch must be reset for a new equivalent period.

During this period, all information remains accurate as long as the watch does not stop. If it does stop, corrections and adjustments can easily be made by various correctors located on both sides of the case middle.

Tonda PF Xiali Calendar with the complex information condensed on the dial in Imperial Red.

Hijri Perpetual Calendar, winner of the GPHG 2020 Innovation Prize.

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