Premiered as a limited edition at Patek Philippe's "Art of Watches" exhibition in New York in 2017, Reference 5531 now enters the regular collection. This is the first ever pairing of two of the manufacture's signature complications - a minute repeater and a world timer with a major innovation. Whereas other world timers sound home time, this model always chimes local time, shown by the city at 12 o'clock and displayed on central hands. This world-first comes courtesy of a new proprietary calibre, the R 27 HU, with a 22k gold mini-rotor that is recessed into the movement and gongs for the minute repeater attached not to the mainplate but to the case middle. The centre of the dial is a showcase for Patek Philippe's rare handcrafts, with a depiction of Lake Geneva and its shores in cloisonné enamel.