The Audemars Piguet Royal Oak Perpetual Calendar watch solves an age-old watchmaking problem

Audemars Piguet’s new Royal Oak Perpetual Calendar is a very clever piece of engineering, an answer to a problem that’s been annoying watchmakers and collectors for decades, which is this. QPs, as these watches are known (from the French, Quantième Perpetuel), are designed to faithfully track the date over leap-year cycles, with some even accounting for the leap day to be skipped at the end of the century, an ability that is somehow beguiling despite having almost no practical use at all.

Quite apart from the status symbol value these watches have (they’re reassuringly expensive), QPs talk to the way watches track time in fractions of a second but are built to last decades, the purest antidote to built-in obsolescence available; they represent a level of patience and long-term thinking we all aspire to.

However, all that timeframe shifting comes at a cost – should these watches ever get left to run down or need a service or fall victim to restless fingers (and they will), the calendar will need to be reset. That means interfering with a delicate complex of gears that are designed to make their stately evolutions using the minimum of energy; consider that one revolution of the month wheel is derived from 126 million ticks.

Traditionally, the answer has been to have various pushers (that need special tools) to let you change the day, date and month and, because the system is so delicate, you can’t change the date or set the time for the hours around midnight. And even if it is safe to set the date, you need to do it in a fixed order. This is not exactly elegant engineering. And don’t even think about the loss of water-resistance all those pusher openings create.

Watchmakers from Patek Philippe downwards have been developing tweaks and workarounds to make things easier, but Audemars Piguet’s new movement is the most complete answer yet – everything is adjustable, at any time, in any direction from the crown. And, as with all proper watchmaking, the ‘how’ doesn’t get in the way, all the cams and wheels doing the work are accommodated within a movement that’s a remarkably slender 4.1mm. Which makes the Audemars Piguet Royal Oak Perpetual Calendar a truly refreshing leap forward.

audemarspiguet.com