Patek Philippe Ref. 5236P: In-Line Perpetual Calendar

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The Patek Philippe Ref. 5236P-001 perpetual calendar just made history as the most recent attempt to reinvent this particular complication. There is a lot to say about this development, and the new movement that goes with it, but we make a note here that this will not be an extensive dive into the piece. That will come after we have seen the watch in person, which in Singapore, will be this month. Think of this as an extensive teaser, inspired by the extensive and impressive Patek Philippe Ref. 5236P technical presentation.

It is not publicly available, but some of you will no doubt have seen it. Anyway, on with the show. The Patek Philippe Ref. 5236P-001 is an impressive, newsworthy and perhaps totally unexpected watch. As a result, the world’s most famous family-owned watchmaking firm Patek Philippe gets the honour of having two same-day posts from us on their Watches & Wonders 2021 releases.

While we would like to claim that this is because the watches are simply that good, it is actually because there were two staggered releases from the Genevan brand. For enterprising PR executives looking for a logistics carnage, that is a neat trick to take note of. Of course, it goes without saying that to work this exploit, a given brand first has to have oodles of credibility and is able to generate a glorious amount of reader interest.

Honestly, all Patek Philippe had to say is that there is a new perpetual calendar for 2021, and the watch-loving world would have made time for it. The brand could do it tomorrow, and we would rearrange our day (but seriously, if you are reading over there at the manufacture, please don’t). As it is, we do not have the space here for the excellent Ref. 6119 (in two gold models) or any of the novelties. It will already be awkward to adequately cover Ref. 5236P.

If you want to know at first glance what makes Ref. 5236P special, take a gander at the window at 12 o’clock. This in-line display of day-date-month is uncommon in watchmaking, and it is unheard of for perpetual calendars. That of course makes this a world’s first, but why? A natural question, to be sure, but simply consider that this display must mean there are four independent discs fighting for space in this section of the dial.

Patek Philippe explained that there are indeed four discs here, one for the day, two for the date, and one for the month; all four are coplanar, which means they share the same plane rather than being at slightly different levels. The principal advantage of this architecture is maintaining a slimmer profile for the new 31-260 PS QL movement with micro-rotor (coming in at just 5.8mm).

This explains how Ref. 5236P manages to measure just 11.07mm thick, which is still a little too thick to comfortably fit under most shirt cuffs we think. This no doubt fits into Patek Philippe President Thierry Stern’s keen interest in shooting for maximum elegance in the thickness of mechanical movements.

Patek Philippe has plenty of perpetual calendars in its range, including a 1972 pocket watch that inspired the 2021 Ref. 5236P. Indeed, it has plenty of contemporary wristwatches with this wonderful complication, as everyone no doubt knows. There are actually a lot of base movement improvements here, but we do not have the space to cover it yet – we have not even mentioned the day/night indicator, the moon phase display and the leap year function in Ref. 5236P.

This is because just that in-line day-date-month display required 118 additional parts (compared with regular perpetual calendars), so we cannot get it out of our heads. The coplanar arrangement of the four related calendar discs also involved the implementation of a double ball bearing system, for which there is a patent pending.

There are two more patents involved in the making of the new calendar system for Ref. 5236P – one for the mechanism that prevents jolts and shocks from disrupting the units wheel, and another for the system that immobilises the units disc during the transition from 31st to 1st.

We will close on that in-line day-date-month because it is certain to cause a certain degree of consternation among some collectors and the wider world of Patek Philippe enthusiasts. At the same time, at this level, a construction quirk like this is perhaps invaluable. This story continues in the coming issue of WOW, and then it will return online.