Matching legibility with design is often one of the great challenges watch designers encounter with the prized perpetual calendar complication. After all, packing in the day, date, month and leap year all in a 40-odd millimeter diameter dial, while keeping to house codes for designs, is a fine line to thread.

Chopard’s own first experience with the perpetual calendar came in the ’80s and ’90s when it first began to develop its own perp cals. The earliest examples of its full calendar wristwatches were in the Luna d’Oro collection, a complete calendar with moonphase display and a day and month window as well as a date hand. What’s interesting here is the brand’s experimentation in case materials: bi-metal titanium and yellow gold models were some of the references created.
Chopard and Svend Andersen
The independent watchmaker Svend Andersen is best known for his creation of the Perpetual Secular Calendar, a perp cal that’s accurate to 400 years. What does that mean? Most perpetual calendar watches are accurate to the year 2100, which is in fact not a leap year because it’s a centennial year that’s not divisible by 400. Andersen’s Perpetual Secular Calendar is accurate to the year 2400.

However, during the ’90s, Andersen was looking to industrialise another perpetual calendar, a retrograde date perpetual. The date display, which sat on a retrograde display, would jump back to ‘1’ when the end of the month was reached, regardless of whether it was the 28th, 29th, 30th or 31st. Truly an impressive design.

Chopard acquired the rights to Andersen’s design and developed it with a base Frederic Piguet caliber, adjusted to its standards. This became the Luna d’Oro, a special edition with a gold moon and ran in a limited series. A gold and platinum edition of the watch were issued. Other variants of the Luna d’Oro were also introduced with a 48-month leap year indication.

Chopard further advanced along the path of complicated timepieces with the reference 36-1224, a chronograph and perpetual calendar that was powered by the Jaeger-LeCoultre 889/1 caliber, featuring overlapping indicators that kept the dial very legible despite its complexity. After all, what’s the point of having all of these instruments on the wrist, if you can’t decipher them?

Doing It Themselves
All of these developments led to the introduction of Chopard’s own L.U.C 96 QP perpetual calendar movement in 2005, based off the 1.96 automatic base caliber of the maison. A large date window, along with date and month counters, made the watch impressively easy to read off. More notably, the calendar operations are instantaneous jumping displays. A day and night indicator as well as an orbital moonphase display only made the watch more interesting, with a choice of Northern or Southern Hemisphere constellations on the moonphase.

A 2012 edition of the Lunar One introduced new improvements. The L.U.C 96.13-L automatic caliber bears both the Geneva Seal as well as C.O.S.C certification, a 70-hour power reserve, a moonphase display accurate to one day in 122 years and instantaneous jumping calendar display. The watch was issued in many variations, including gem-set models.

But what was possibly the most surprising release of Chopard’s perpetual calendar came in 2016, the last leap year, when the brand introduced a steel model of the watch, the L.U.C Perpetual Twin, in a 43mm stainless steel model with twin barrels (hence its name) and delivering a 65-hour power reserve.

That same year, the brand also released the L.U.C Perpetual Chrono, combining two of the industry’s favourite complications — a vertically coupled flyback chronograph and perpetual calendar on a Fairmined gold case with a hand-wound movement, the L.U.C 03-10-L. The doubly-certified movement bears a familiar dial design, with chronograph counters stacked over the perpetual calendar’s display for legibility.

More recently, the 2017 edition of the Lunar One in platinum with a deep blue sunray finish, adds to the beauty of the watch. It’s a striking timepiece and remains a rare industry standard, given that it’s automatic winding and has a chronometer and Genevan Seal certification.
It’s been a few years since we’ve seen a perpetual calendar from Chopard, although the complication has been added to other models from the brand. However, for the perpetual calendar lover, the Lunar One is a model to appreciate, especially given how the brand has not only kept the name of the watch running, but its design and style a steadily evolving one over the years.