The ref. 725 perpetual calendar is where it all begins: the design language that would define refs. 1518, 2499, 3970, 5970, and 5270 traces directly to this model. Its DNA—moon-phase placement and the balance of the subsidiary dials—echoes through Patek Philippe calendar watches from the mid-20th century onward. Beyond its aesthetics, the ref. 725 embodies the uncompromising quality that is quintessentially Patek Philippe.
Powered by a Victorin Piguet & Cie caliber 17-170 perpetual calendar, the ref. 725 is a true instantaneous display with date at 3 o’clock, day at 9, month at 12, and moon-phase at 6. The movement is adjusted in eight positions and finished to an exceptional standard.
Dials were supplied by Stern Frères—typically silvered with applied gold indexes—paired with either feuille or dauphine hands. The final series, largely from the 1970s and known as ref. 725/4, introduced the linear “American straight-line” perpetual calendar (a single aperture showing month/date/day), neatly bracketing the lineage between the layouts of the refs. 1518 and 3448.
Cases were made by Wenger, who would later produce the cases of the ref. 2499. Measuring 46 mm by 10 mm, the ref. 725 is an ideal dress-watch proportion for its era, with three correctors: day/date at 9 o’clock, moon-phase at 7, and day-only at 3.
Production was extremely limited—fewer than 100 across all configurations—and fewer than 21 examples are known in yellow gold. Five reside in the Patek Philippe Museum, underscoring the reference’s historical importance.
This fresh-to-market example was retailed by Tiffany & Co. in 1946 and still is accompanied by its original Tiffany & Co. box. Remarkably well preserved, this example belongs in a museum – or your collection.
