Patek Philippe’s World Time watch, known as the Heures Universelles ( or HU) has a rich history rooted in the innovative mechanical design of independent watchmaker Louis Cottier. Patek Philippe was the first company to produce a series of wristwatches using his system, which allows the wearer to view all 24 global time zones simultaneously. The concept originated with Cottier, who patented his world time mechanism in 1931. Patek Philippe quickly recognized its potential and collaborated with him, producing their first world time wristwatches in the late 1930s. The mechanism was first implemented in a Calatrava, reference 96, in 1937, and two years later, in 1939, it appeared in the reference 1415. This first serially produced world time model featured a manually rotating bezel engraved with city names. Pocket watches with the complication were also created during this era, including rare examples with elaborate cloisonné enamel dials depicting world maps—undoubtedly among the most beautiful watches ever made. In the 1950s, Patek introduced a significant improvement with a second crown at 9 o’clock, allowing independent adjustment of the inner city ring and 24-hour display. This more user-friendly system appeared in the reference 2523, making the watch ideal for travelers. By the 1960s, Patek Philippe stopped producing world time wristwatches, perhaps due to a perceived lack of demand or the passing of Louis Cottier. Whatever the reason, the complication was revived in 2000 with the introduction of the reference 5110 in various metals. This model featured a patented pusher at 10 o’clock, allowing the user to advance the hour hand, 24-hour disk, and city ring simultaneously with a single press. The example we have on offer is a reference 5110G, with the “G” denoting the 18k white gold variation. The 37 mm case has a slim, elegant profile, featuring the 10 o’clock pusher and a refined crown guard. A sapphire case back allows the wearer to admire the 22k gold micro-rotor of the automatic caliber 240HU pressing the pusher at 10 o’clock, the city disk can be aligned to the correct time zone. Next, pulling the crown to the first position allows you to set your local time. At the same time, the 24-hour disk would rotate counterclockwise, advancing one hour with each adjustment to display the correct time across all 24 of the world’s time zones. The true showstopper is the opaline, engine-turned (guilloché) central dial, surrounded by 24 cities rendered in a charming font. The hands are a clear nod to the vintage references, including the 2523, 1415, and the affiliated pocket watches. The tactile feel of the 10 o’clock pusher exemplifies Patek Philippe’s mechanical excellence. While it may be difficult to appreciate in words, pressing it immediately demonstrates the precision and quality of the mechanism, we promise! This world time is fitted with a slightly used original Patek Philippe leather strap and the original 18k white gold Patek Philippe folding clasp. Additionally, it comes with an Extract from the Archives confirming a sale in May 2005. This fine watch has been fully serviced by our watch maker; ready for years to enjoy. We think this is one of the most romantic watches in Patek’s more recent lineup—and a truly cool complication to own! Let’s get you this World Time. Specifications: Patek Philippe World Time reference 5110G 37 mm 18k white gold case with display case-back Opaline colored dial with center guilloché “Heures Universelles”, world time 24 time zones display complication Case no 3215xxx / movement no 4297xxx dating to 2005 Automatic cal 240 HU(Heures Universelles) with 22 k gold microrotor Patek Philippe leather trap with 18k white gold Patek' folding clasp Extract of the archives from Patek Philippe stating a sale in 2005 Fully serviced by our watch maker One-year mechanical warranty Free worldwide Fedex Priority shipping