Review: Patek Philippe In-line Perpetual Calendar 5236P

Ever looked at a Patek Philippe perpetual calendar watch and thought, “That’s clever and everything, but boy is it hard to read”? Yeah, me too, and apparently so did Patek Philippe, because they came up with this, the In-line Perpetual Calendar 5236P.

Background

What do you think of when you hear the word “watchmaker”? I suppose it’s a person or a company that makes or services watches. And by watches I mean the case, dial, hands, movement, bracelet, etcetera. Thing is, that’s not really the situation, and rarely is. Watch brands would have you believe all that comes from under one roof, but the reality is that’s only true of the biggest. Rolex and Patek Philippe, being industry giants, are one of the few, but even they get some bits and pieces made externally.

Now you know that, what we see when we go back in time will make a bit more sense as well. Despite what clever marketing would have you believe, Swiss watchmaking has always been about outsourcing. Right from the very beginning, watch companies simply bought parts from local farmers who made them in their homes during the harsh winters for a bit of extra cash.

Of course, trying to assemble a jigsaw puzzle of parts that came from a group of people who’d never even met each other let alone worked together was always going to be an uphill battle. Many of these movements required a huge amount of modification to even fit. If you’ve ever wondered why very traditional movements have their bridges split, it’s because the tolerances just weren’t there to build them in one piece. A. Lange & Söhne’s three quarter plate is really the watchmaker showing off.

If Switzerland had any hope of competing with the world in the watchmaking field, it was going to have to up its game. And so came the great movement makers: Jean-Marc Vacheron, Adrien Philippe, Jules Louis Audemars. These guys knew their stuff when it came to mechanical timekeepers. Each one was a genius that could build any complication in any configuration, as such earning the reputations that live on today.

Here’s the thing about genius: it usually has no room for anything else. You’ll notice all the names above come with a partner: Vacheron Constantin, Patek Philippe and Audemars Piguet. Many times, the partner—who may also have been an accomplished watchmaker, but the lesser of the two—would take on business duties, touring the world and racking up sales. It was their job to try and persuade the genius watchmaker of the duo to make what would actually sell.

But the watchmakers didn’t really care for the commercial side so much, and sometimes there was tension between the two parties. “Do it better if possible, and that is always possible,” Constantin wrote to Vacheron in 1819. You see, these genius watchmakers didn’t really care much for the end user. They cared more about watchmaking perfection, and if that meant making a perpetual calendar very difficult to read, then so be it. Dials, windows, sub-dials—as far as the display was concerned, if it existed it was done.

Hands, crowns, cases and all the rest were dealt with by someone else, usually another company. Sometimes watchmakers like Audemars Piguet would just make movements for watches sold by better-known brands like Cartier. And so that’s how we’ve ended up with the tradition of the perpetual calendar looking like a hot mess. It only took Patek Philippe 96 years since it created the world’s first perpetual calendar wristwatch to sort it out.

Review

The typical Patek Philippe—and, indeed, Swiss—perpetual calendar layout isn’t impossible to read, it’s just not easy. You’ve got your day and day/night over on the left, the month and leap year on the right, date and moon phase down below. It’s all a bit shoehorned in there, using rules that aren’t consistent to try and fit it all in. For example, the day has dots between them to divide them visually, but the dots between the months and dates are extra months and dates so they could squeeze them in. Also annoying is that there’s no room left for a running seconds hand, so whilst the watch can keep the date precise for decades and decades, you won’t know if the time is accurate now.

Patek Philippe is well aware of the annoyance of that traditional style, since with its annual calendars it’s been experimenting with a much more readable system. With no pesky leap year to deal with, the day, date and month can be given their own crystal-clear windows, seated alongside one another in a way that’s actually designed for normal human eyes.

Now, Patek Philippe have already solved this problem for the perpetual calendar with a pocket watch made in 1972, but of course a pocket watch is a darn sight bigger than a wristwatch so has more room to play with. So, the first thing Patek Philippe did was to choose a base movement that gave them a good starting point, the calibre 31-260. But wait a minute, that movement was for a regulator wristwatch, not a perpetual calendar—how does that make sense?!

When you think about it, it does. A regulator watch splits the hours, minutes and seconds around the dial, which means accommodating a lot of separation of components usually combined into one. Patek Philippe made the movement broad, some 2.5mm bigger than normal, and flat, with a micro rotor for winding, to keep the thickness sensible.

To get an inline calendar at the top needed a similar broad, flat structure, and so, expanded yet another 2mm across, the calibre 31-260 PS QL was born. The result is a very full 41.3 by 11.07mm platinum case—that’s surprisingly water-resistant to 30m. Huh. But where 41.3mm is a pretty beefy case size for a dressy Patek Philippe, the 11.07mm thickness is impressively skinny. How did they manage that?

The answer is so simple it’s almost embarrassing. Like a magician revealing a trick, the answer comes not from complexity, but rational thought. Just like the pocket watch, the day and month are read from small wheels separated into seven and twelve sectors respectively. Where the 5236P differs from the pocket watch is in the date. The pocket watch was big enough to have a single wheel for the date, but that wouldn’t work here. A date wheel is usually the size of a whole wristwatch movement so it wouldn’t fit up at the top. The answer was a big date, where the two digits are separated.

Problem with the big date solution is that, one, the disks overlap which would make the watch too thick and, two, they would take up the space the day and month wheels were sat in. So Patek Philippe went a different route. By separating the numbers into two very skinny disks, they could not only sit next to each other without incurring any extra thickness, they could also sit around the day and month wheels and take up barely any extra room.

The result is a fully flat, completely unbroken, in-line display of day, date and month, exactly where you want to read it in exactly the format you want to read it in. And there’s so much space left over on the deeply grained blue dial that not only can the day/night indicator, moon phase and leap year be consigned very neatly to the lower half, there’s finally room for a running seconds, too.

Finally! Finally. Patek Philippe has done it. It’s taken a long time, but the In-line Perpetual Calendar 5236P without doubt proves that Patek Philippe is a true watchmaker, not just dining out on its heritage but able to move the mechanical complication game forward too. It doesn’t come cheap, mind: $130,110. That’s simply how much it costs to persuade a watchmaker to sacrifice optimal mechanical design for a better user experience.

Looking for a pre-owned Patek Philippe watch? Click here to shop now