Audemars Piguet introduced the perpetual calendar complication to its iconic Royal Oak collection in 1983, 11 years after the debut of the Royal Oak model, marking a significant milestone in integrating haute horology into its bold, modern design language. Among the earliest perpetual calendar Royal Oaks was the refined Reference 25654, produced from 1983 to 1998. This reference is believed to be limꦺited to just 422 examples in yellow gold, further cementing its status as a rare and highly sought-after collector's piece.

At the ▨heart of the Ref. 25654 waꩲs the Caliber 2120/2800, an automatic movement renowned for its precision and ultra-thin profile. This movement was based on Jaeger-LeCoultre’s legendary Caliber 920, developed in 1967 with support from Audemars Piguet. The Cal. 2120 was a collaborative triumph of horological engineering, also adopted by esteemed watchmakers such as Patek Philippe and Vacheron Constantin for their high-end timepieces. Integrating this movement into the Royal Oak case exemplified Audemars Piguet's mastery in combining technical sophistication with aesthetic innovation.

In 1998, Audemars Piguet introduced the Reference 25820 as the successor to the 25654. This updated model featured the Caliber 2120/2802, which in📖cluded a leap 💟year indicator—an enhancement first seen in the limited-edition Reference 25810. The addition of this complication offered improved functionality and reflected Audemars Piguet’s commitment to pushing the boundaries of technical artistry within the Royal Oak collection.

These perpetual calendar models are more than just timepieces; they represent an enduring legacy of Audemars Piguet’s dedication to precision, innovation, and timeless design, resonating deeply with collectors an🦩d enthusiasts alike.