Why watchmakers are obsessed with the lunar cycle

Time began with the sun and the moon: the observed rising and setting of the sun giving the day, the waxing and waning of the moon providing months, and the earth’s orbit of the sun supplying the year. Thanks to an understanding of the cycle, we began to anticipate the seasons, the migratory habits of the animals we hunted, and then, later, the times at which to sow and harvest crops. 

Things have moved on a bit since the Palaeolithic Age. But this year there seems to be something in the horological zeitgeist that wants to reconnect us with the origins of time. Of all “mainstream” watch complications, the moonphase indicator, which displays the waxing and waning of the moon over roughly 29 and a half days through an aperture in the dial, is arguably the least directly useful to the wearer. It may also be be the reason that I like it. 

Christopher Ward steel C1 Moonphase, £2,155

Blancpain red-gold Villeret Quantième Perpétuel, £47,100

Frédérique Constant steel Classic Moonphase Date Manufacture, £3,495

IWC Schaffhausen platinum Portugieser Eternal Calendar, about £150,000

The moonphase is as much a piece of horological self-expression as it is a complication. At this year’s Watches and Wonders fair it was striking just how many brands presented moonphase watches. At the more affordable end of things Raymond Weil had the attractive Millesime Automatic Moonphase in denim blue, while Frédérique Constant premiered the Classic Moonphase Date with a dial in green. 

More rarefied was Laurent Ferrier’s Classic Moon, an exquisitely balanced design with the moon and stars filled with Super-LumiNova so that they twinkle at night. “I felt that traditional moonphases were a little sad,” says Ferrier of this twist. “This is more spectacular.”

I felt that traditional moonphases were a little sad. This is more spectacular

And as Jaeger-LeCoultre revealed with its Duometre Chronograph Moon, the indicator can be used to great conceptual effect in combination with other complications. “We put the moonphase in to balance the counters on both sides even if it meant creating a new calibre,” says Jaeger-LeCoultre CEO Catherine Renier. But there is more than aesthetic equanimity at work here; there is a symbolic, almost philosophical quality about pairing the moonphase, which creeps forward almost imperceptibly, with the frenetic action of the foudroyante that divides each second into six parts with a hand that moves so rapidly that it is almost a blur. “There is precision and there is an intellectual dimension,” says Renier. “The slow complication balances the fast.” 

Just because it is not prosaically useful, it does not follow that it is without meaning. “The moon has an appeal on many counts,” says Mike France of British watch brand Christopher Ward. “For years the moonphase was the most asked-for complication, and we did not have one.” Now he has two: the C1 Moonglow and a new C1 Moonphase launched in November. France sees the appeal as universal. “We associate poetry, romance, mythology, even cartoonery, with the moon.”

Mention of cartoonery immediately evokes one of this year’s hottest launches, “Mission to the Moonphase”, the latest in the phenomenally successful Omega x Swatch Moonswatch series, on which the indicator features Snoopy, Nasa’s safety ambassador, napping in a crescent moon.

The moonphase is usually seen in its most classic form on perpetual calendars, such as the latest Villeret Quantième Perpétuel from Blancpain. Its characteristic human-featured moon is regarded as a symbol of the brand’s rebirth in the wake of the Quartz crisis, as well as a whimsical riposte to the inhuman precision of the modern watch.

Raymond Weil steel and rose-gold Millesime Automatic Moonphase, £2,075

Laurent Ferrier steel Classic Moon, SFr70,000 (about £60,100) excl VAT

Omega x Swatch bioceramic Mission to the Moonphase Full Moon, £270

Jaeger-LeCoultre platinum Duometre Chronograph Moon, £81,500

There are times when the wrist is simply not big enough to accommodate all the lunar information that you might need, as was the case with the Berkley, the massive 63-complication “pocket” watch made by Vacheron Constantin, on which a moonphase occupies the top spot at 12 o’clock. But it is its mastery of the intricacies of the Chinese lunisolar calendar that sets this watch apart.

“The lunar calendar is driven by algorithms, which are necessary to take into account all the irregularities of the Chinese calendar,” explains Christian Selmoni, Vacheron’s head of style and heritage. “In order to reconcile the lunar calendar with the solar calendar, you have to add what they call embolismic months every two or three years on an irregular basis over a 19-year cycle. In the end we had to make two mechanisms, one driving the lunar calendar, one driving the solar calendar.” (I feel slightly less stupid when I learn that it took one of the three watchmakers who made this piece a year to calculate the algorithms and transcribe them into mechanisms to choreograph this astronomical dance.)

The moonphase indicator on the Berkley is accurate for more than a millennium, requiring adjustment by one day every 1,027 years, which is impressive, but when compared with another of this year’s launches is but a stroll in the lunar foothills.

This year the boffins at IWC devised a moonphase reduction gearing system, comprising three wheels, that delivers a moonphase that will run for 45 million – yes – years before it is a day out of sync with the actual phases of the moon. Under such circumstances I think it is permissible to overlook the slight exaggeration in the name: Eternal Calendar. The practical values of such an indicator are not immediately apparent to me, but I suppose that humankind has 45 million years to figure that out.