Patek Philippe’s most buzz-generating release at its inauguaral Watches & Wonders appearance earlier this month was undoubtedly the green-dialed Nautilus that marked the finish line for the production of that sport-luxury reference. But the manufacture’s most technically significant new model, which made its debut in the wake of that release, came from its venerable, classically elegant Calatrava collection. The new Ref. 5236P-001 In-Line Perpetual Calendar offers an all-new (and patented) take on the perpetual calendar wristwatch.

The Ref. 5236P-001 is Patek’s first wristwatch with an “in-line” calendar display.

The new watch features the day, date, and month on a single line in a long, horizontal aperture beneath 12 o’clock, an arrangement that Patek Philippe has used in pocketwatches throughout its history ? like the Ref. P-1450 from 1972, a piece now on display at Patek’s museum in Geneva ? but never before in a wristwatch. Presented in a 41.3-mm case made of 950 platinum, with a lacquered blue gradient dial and housing a new self-winding movement, the model further solidifies Patek Philippe’s multi-generational expertise in crafting perpetual calendars for the wrist, which began with its first such model in 1925.
The lacquered gradient blue dial features hands and indices in white gold.

One of the biggest challenges Patek’s watchmakers had to overcome was creating a legible calendar display on a sing...