Released in 2021, the Patek Philippe 5905/1A Chronograph Annual Calendar represents the marriage of arguably the two most practical complications: the Annual Calendar and the flyback chronograph. Interestingly, this watch was unveiled in the same year as the 5226G that we recently covered — another timepiece that mates a pair of extremely practical complications. Based on earlier Patek annual calendar references and introduced to the modern collector, the 5905 serves as a reminder of what Patek does best: honoring historical precedent while respecting modernization and innovation.
In 1996 Patek wanted to extend the calendar complication to a broader audience. Recognizing that not every customer would be in the market for a perpetual calendar, it was time for a more approachable complication that would bridge the gap between its entry-level Calatrava and the prestigious Grand Complications. The 5035 Annual Calendar, released that year, served as the ideal middle ground, requiring a date adjustment only in March. With easier and more affordable servicing, the new Annual Calendar became a staple of the “Complications Collection” and has become one of the most popular and well respected releases in the brand’s history.
Since the 5035’s release, Patek has created many annual calendars including the 5036, 5135, 5146 and 5205. Then, in 2006, Patek coupled the annual calendar with a flyback chronograph for the first time with the groundbreaking 5960 — a combination of complications incredibly practical, this release became an instant hit. In 2015, Patek brought the very first 5905, initially launched in platinum. Now, for the first time in Patek Philippe history, the Patek Philippe 5905 is available as a steel case and bracelet combination with the reference 5905/1A.
The Patek Philippe 5905/1A is equal parts elegant and sporty. Fashioned from stainless steel with a solid link bracelet, Patek has intentionally created an offering that brings an Annual Calendar chronograph into a more casual playing field. Nonetheless, Patek has condensed the day, date, month, and chronograph registers into a tastefully simple set of displays. This versatility is at the core of every facet of the watch’s execution. The stainless steel bracelet artfully incorporates contrasting brushed and polished surfaces, showcasing Patek’s mastery of fine finish work and nodding to the bracelet design of many Aquanaut references.
Unlike most metal bracelets in the watch world, the center links are brushed and the outer links are polished on the 5905/1A. This immediately draws attention to the concave polished bezel and olive green sunburst dial. The swirling, gentle curves of the case all construct the perfect frame for the dial, allowing the case and bracelet to be visually interesting and detailed, without detracting attention from the dial. The dial is laid out in concentric chapter rings and within these rings rest the annual calendar functions. Intersecting these circles at six o’clock the chronograph minutes divide the dial evenly and help balance the dial’s layout. At the center of the 60 minute chronograph scale a AM/ PM indicator turns blue in the nighttime hours. During these hours it is advised to avoid adjustment of the calendar mechanism, as it may have deleterious effects on the movement.
White gold applied indices further subdivide the dial into sectors, with beveled top surfaces meeting at a fine line. Detail work continues to the lugs, which feature concave scalloping that complements the bezel’s concave profile cohesively. The flanks of the case and pushers all feature mirror polishing and a slight radius, softening lines and refining aesthetics. The layout of this dial clearly reflects the historic journey of Patek’s past annual calendar references. The 5205 Annual Calendar features a very similar dial layout minus the chronograph additions. This allows the 5905/1A to feel well situated within the Patek lineup, with notable attributes of Patek DNA incorporated into 42mm case dimensions.
The Patek 5905/1A is equipped with the caliber CH 28-520 QA 24H. Robust and refined, the movement maintains the elegant yet utilitarian spirit of the rest of the piece. Fitted with a 21K yellow gold central rotor, this caliber provides the incredible array of finishing details that are the fabric of the Patek Philippe reputation. Perlage, anglage, Geneva striping, brushed elements and polished elements all contribute to subtly contrasting details. This movement has a three dimensional appearance and manages to pack a considerable pairing of complications into 7.68mm of movement thickness. While most brands would struggle to create a timepiece with this combination of complications, Patek manages to execute their annual calendar chronograph in a slim package.
The flyback chronograph element of the movement is in a vertical clutch column wheel configuration. Patek claims that this orientation allows the chronograph hand to be used as a running seconds hand, as vertical clutch column wheels reduce stress on the movement when the chronograph function is engaged. Without the vertical clutch column wheel, the teeth of the chronograph are in constant friction, increasing stress and rubbing within the internals. Simultaneously working to combat the implications of friction, Patek has equipped their winding rotor with ceramic rotor bearings, contributing to smooth winding. This movement is guaranteed by Patek to be accurate within -3/+2 seconds per day and has a reliable power reserve of 55 hours.
Versus the Competition
The Patek Philippe 5905/1A is a unique coupling of complications. The most direct comparison to the 5905 would be the Patek Philippe 5960. The 5960 shares an incredibly large number of characteristics with the 5905, although the 5960 dips further into the sports aesthetic despite being fashioned from white gold (and in rare cases platinum). Next to the 5960, the 5905 feels more refined and mature, although its stainless steel case and bracelet practically make it more robust. Collectors with smaller wrists will favor the slimmer dimensions of the 5960, while those with larger wrists will gravitate towards the bolder proportions of the 5905.
The Patek Philippe 5205 also makes for a sound alternative, providing the annual calendar function sans chronograph. For a collector looking for a dedicated annual calendar, the 5205 shares many characteristics with the 5905. Namely, the concentric chapter rings and calendar layout. On the 5205, the chronograph hand is replaced with a running central seconds, and the chronograph register at 6 o’clock is replaced with a moonphase indication and 24-hour scale.
The collector that will gravitate most towards the 5905/1A is one with an appreciation of practical, yet mechanically impressive complications. Preferring a sportier appearance and Aquanaut-style bracelet, they will appreciate the inherited attributes of historical references while simultaneously desiring the luxuries of a distinctly modern Patek Philippe. Most of all, the 5905/1A will be appealing to those that appreciate the dual identity the 5905 holds; its modern proportions and casual design, coupled with its high level of finishing allow this timepiece to be suitable for many occasions. This versatility makes the 5905/1A one of the best everyday options from Patek Philippe’s Complications line.
The Patek Philippe 5905/1A is the culmination of years of historical references. Merging the famous Annual Calendar complication with a flyback chronograph, this Patek is a striking statement piece accentuated by an olive green radiant dial. Alongside the other Patek Philippe Annual Calendars, the 5905 shares an overarching theme of exceptional quality and attention to design. Distinctly Patek Philippe in styling, the 5905 represents the epitome of the brand’s philosophy; continued incremental improvements and refinements are at the core of the brand’s identity, informing every adaptation in the quest to reach perfection.