Audemars Piguet Perpetual Calendar, 25657PT, Platinum

Sold under the margin scheme. Learn more

First launched in 1978, the Quantième Perpétuel by Audemars Piguet was the world’s thinnest automatic perpetual calendar. The reference 5548 was the first reference of this newly released perpetual calendar, birthing a category of watches which has taken on many different forms. Sources note that total production for the reference 25657* stands at 1821 watches, with just 128 in platinum, making this example fairly rare and not often seen on the market.

Leap Forwards of Perpetual Calendar

The first perpetual calendar pocket watch was invented by Thomas Mudge in 1762, yet it wouldn’t be until 1925 when Patek Philippe produced the first perpetual calendar wristwatch. That’s how hard it is to miniaturise this complication, just so that its wearer isn’t thrown out of sync for a moment every four years.

Certainly, the complexity of this complication isn’t just about scale. It’s about energy. If a chronograph requires a lot of energy just to move those three extra hands, now imagine the energy demands of a watch whose entire mechanism needs to be constantly running, even while it appears to be doing not much at all. This requires minimal friction, minimal weight and whatever else can be done to conserve energy.

All of which begs the question, if perpetual calendars can not only be challenging to make, but even to own, what quite is their appeal? Michael Friedman, who holds the fantastic title of ‘head of complications’ at Audemars Piguet – makers of rods for its own back, and hence the RD2, the world’s thinnest self-winding perpetual calendar watch – gets philosophical on this question. If, he says, watches are so often celebrated for their precision in the moment, for their nowness, for splitting seconds, the perpetual calendar celebrates slow time. Indeed, the very name says it all: the perpetual calendar might as well be called the forever watch.