Perpetual Calendar 3940 Yellow Gold / Painted Roman

In Context

At 36 mm it is classically proportioned: the size a dress watch was understood to be for most of the twentieth century, and small enough to sit under a cuff. The case back is open, so the movement is visible without taking the watch apart, and the sapphire crystal will resist everything short of deliberate abuse. Rated to 30 m, it is protected against rain and splashes and nothing beyond that.

The movement winds itself from the motion of your wrist. 48 hours of reserve is enough to set it down on Friday evening and find it still running on Monday. At 21,600 vph the seconds hand advances 6 times a second, the slower and more audible rate of an older design.

3940J-025 stands on its own in this catalogue — no other reference here shares its base number. It pairs a white dial with a yellow gold case. Beyond the time it carries a perpetual calendar.

The perpetual calendar built on the 240, and the movement behind Patek's first self-winding perpetual calendar with moon phase — the reference 3940 of 1985. The calendar works sit as a module over the ultra-thin base, and the whole assembly still measures 3.75 mm. Thinness is the point: a perpetual calendar is normally a thick watch, and the 3940 established that it did not have to be.

21 other watches in the library run the Patek Philippe 240 Q.

Patek Philippe

Twenty-4 Perpetual Calendar Rose Gold / Green

7340/1R-010 · 36 mm

Patek Philippe

Perpetual Calendar 5327 Yellow Gold / Ivory

5327J-001 · 39 mm

Patek Philippe

Perpetual Calendar 5940J Yellow Gold / Silver

5940J-001 · 37 mm

Patek Philippe

Perpetual Calendar 5039 Yellow Gold / Silver

5039J-001 · 36 mm