We owe the world time display on the Patek Philippe Reference 5230 (and indeed on other high-end world time watches) to a 1953 patent by Louis Cottier, a watchmaker from Carouge, who succeeded in displaying on a watch dial the notion of coordinated universal time devised by Sandford Fleming. The Canadian engineer Fleming had imagined dividing the world into 24 time zones and placed Greenwich as the prime meridian. Cottier’s patented invention involved translating this lateral approach (seen as losing an hour if travelling west on the map and gaining if travelling east) to a circular form that could be used on a watch dial. The result is the now-familiar arrangement of a peripheral disc containing the names of the cities representing these 24 time zones and a separate disc showing the 24 hours of the day. The mechanical implementation is relatively simple: press on the pusher at 10 o’clock and the hour hand will advance in one hour increments, while the city and 24-hour discs move in the opposite direction by one-hour increments. The only difference is that the former operates on a 12-hour scale and the latter on a 24-hour scale. This is a patented function by Patek Philippe that associates the world time and travel time functions and allows a second hour hand to be disengaged from the watch movement without affecting its operation.

Reference 5230G © Patek Philippe

In the Reference 5230 these discs are mounted on the calibre 240 ultra-thin self-winding mechanical movement, which dates back to a design patented in 1977 and is just 3.88mm thick, largely thanks to a micro-rotor that is flush with the level of the movement bridges. Over the years this calibre has evolved to incorporate Patek Philippe’s own patented innovations, such as the Spiromax® balance spring, and its precision surpasses the requirements of chronometer certification so that it can meet the stringent conditions of the Patek Philippe Vintage Watches Ebay Seal, which requires a mean deviation in daily rate of between -3 and +2 seconds.

© Patek Philippe

Like the movement, time zones have also evolved over the years, which has led Patek Philippe Watch 175 Price to update its world time display on the Reference 5230, replacing Riyadh with Dubai, Rio de Janeiro with Buenos Aires and Brisbane with Noumea, as well as adapting the time zone of Moscow, which is now at UTC +3. The company has also used the opportunity to make a number of subtle changes to the previous world time models, reducing the case size by 1mm (from 39.5mm to 38.5mm), changing the crown guard, the lugs and the bezel, as well as opting for a hand engine-turned decoration at the centre of the dial (using a new distinctive “basket-weave” pattern) instead of the guilloché used on its predecessors (Ref. 5110 and 5130). A new pair of hands also graces the dial, with a lozenge-shaped minutes hand and a pierced hour hand that looks like a traditional “Ardi” style hand with an added arrowhead tip.

One thing I must add is that I’m usually not the biggest fan of five-link bracelets, and this taste remains unchanged here. Above you may see the white gold and blue dial 5960, which I really quite like on the leather strap, but the bracelet on the steel model is just not doing it for me. It is performed as refined and as well as you can be, though, and the way the curving lugs hug the wrist in a manner in which the five-link bracelet does appears to function as natural fit for the watch.Seen in the caseback and adorned with a 21k gold strand using the Patek Philippe seal, the more in-house 28-520 IRM QA 24H motion is a mouthful, but a very striking and significant one in that. Our David Bredan went into the movement when the previous steel model was introduced and I’ll repeat his overview of the motion here:”The movement indoors (and have a deep breath today) is your completely in-house manufactured CH 28-520 IRM QA 24. That translated into watch-terminology signifies that the motion includes a flyback chronograph, an annual calendar, a power-reserve signal (for exactly what the newest notes as anything between 45 and 55 hours, likely based on for how long the chronograph is in performance), and also a day-night indication. Its foundation movement comprises 302 components, while the clever (and just 2.48 mm thick) annual calendar module adds another 154 parts to that. And while we frequently discuss perpetual calendars–calendars which require absolutely no adjustments until the year 2100–yearly calendars mean a smart transition between the classical calendars.”

© Patek Philippe

These details all add up to a touch of freshness for this longstanding model, which replaces all previous World Time models by Patek Philippe and is available as Ref. 5320 R in 18-carat rose gold and Ref. 5230G in 18-carat white gold, both with exactly the same dial with a white city disc, 24-hour ring with day and night colour segments and the black engine-turned centre decoration. The only difference between the two is that the hands and hour markers match the gold colour of the case. Both models are available at the same price of 42,000 Swiss francs.

Patek Philippe – No Gimmicks, Thank You from Worldtempus.com on Vimeo.