The Audemars Piguet Dual Time reference 25685BA comes from a period when AP was making some seriously interesting watches outside of the Royal Oak. Introduced around 1989-1990, the 25685 was the brand’s first Dual Time wristwatch, pairing a traditional 36mm round case with a surprisingly modern set of complications. The BA designation denotes the 18k yellow gold version, and with its stepped bezel, Roman numeral dial, and relatively restrained proportions, it looks like a proper old-school dress watch until you actually start paying attention to everything happening on the dial.

That dial is really what makes the 25685 special. Along with the central hours and minutes, AP managed to fit a second time-zone display at 6 o’clock, a date indicator around 2 o’clock, and a power-reserve indicator around 9 o’clock without turning the thing into a mess. Inside, early examples used the automatic caliber 2129/2845, based on a Jaeger-LeCoultre ébauche and modified by Audemars Piguet for the additional functions. Later examples received the updated 2229/2845. It is a great snapshot of how high-end Swiss watchmaking worked during this era, when brands like AP and JLC regularly shared technical expertise while still producing watches with very distinct identities.

The 25685BA is also one of those watches that makes you question the idea that an Audemars Piguet needs an octagonal bezel to be interesting. At 36mm in yellow gold, it wears elegantly and a little under the radar, especially compared with the Royal Oaks and Offshores that would increasingly define AP through the 1990s. More importantly, the Dual Time concept did not disappear. AP subsequently brought the complication into the Royal Oak family, using the same basic combination of a second time zone, date, and power reserve. That gives the 25685 an interesting place in the brand’s history: it is a complicated, useful, slightly weird piece of pre-modern AP, and exactly the kind of reference that gets more interesting the deeper you get into collecting.