The Audemars Piguet Royal Oak Perpetual Calendar (ref. 26674ST.OO.1320ST.01) marks a new mechanical chapter for one of the brand’s most iconic complications. Debuting in 2025, this reference houses the newly developed calibre 7138, offering refined architecture in a leaner package while retaining the visual hallmarks expected of the Royal Oak.

Its 41mm stainless steel case, now upgraded to 50m of water resistance, surrounds a classic ""Grande Tapisserie"" dial in deep blue – a colour long tied to the lineage of steel Royal Oaks. The perpetual calendar layout remains intuitive yet intricate, with sub-dials for day, date, month, leap year, and a finely rendered moonphase at 6 o’clock. Calibre 7138 brings improved power efficiency and finishing, although Audemars Piguet has not disclosed an exact power reserve.

As a successor to earlier Royal Oak QPs, this reference balances continuity with discreet technical evolution. The integration of a new in-house movement and refined waterproofing make it one of the most modern—and practical—interpretations of the perpetual calendar in Audemars Piguet’s steel collection to date.