Fraud Blocker 5146, 5205, 5396, 5961, Patek Philippe Annual Calendar: What’s Behind

5146, 5205, 5396, 5961, Patek Philippe Annual Calendar: What’s Behind The Reference Numbers

The Patek Philippe brand is known for pushing the limits of fine mechanical watchmaking and craftsmanship. Each timepiece is not only a mechanical marvel but a piece of art and a tribute to the highest level of excellence in all aspects of Swiss watchmaking. Today, it is one of the most prestigious and renowned brands, with each timepiece being highly sought-after. Among watch connoisseurs, Patek Philippe timepieces are known for the reference number and model names that distinguish which collection a watch is from, or whether the timepiece is for men or women, and the unique attributes of a timepiece. As for the Annual Calendar, we will specifically answer how to identify THE Patek Philippe Annual Calendar.

The Guide To Patek Philippe Reference Numbers

Watch collectors and enthusiasts who are well-versed in Patek Philippe models don’t usually distinguish each unique model by the nickname but rather by the reference number. The numbering format for Patek Philippe models is xxxx/xxxX-xxx. 

The First Digit

To start, let us discuss the first digit. If the first digit is a 3,5, or 6, then the Patek Philippe watch is for men. The reference numbers for women’s watches begin with 4 or 7. The differences among the initial digits, “3,” “5,” and “6,” have more to do with the combination of size and heft (within the same collection), and the complications underneath the surface. 


None of the men's watches with reference numbers beginning with "3" were released in 2021. The more famous of these models, the ref. No. 3970, released in 1986, doesn't have a clear successor as of the 2010s except for the classic ref. No. 5970, which was released in 2004 with the same caliber. Some men's watches beginning with "6" belong to the Grand Complications collection, with more than 41mm dial sizes. Other timepieces whose reference numbers start with "6" are from the Calatrava collection where the “6” is used to distinguish their case diameter from the other Calatrava models. Men's watches beginning with "5" are more or less those in between, except for a few exceptions: the ladies' Luce line from the Aquanaut collection. Wristwatches whose reference numbers begin with "1" or "2" were discontinued decades ago.

For comparison, we will be matching two watches coming from the same family, the Grand Complications. Since it belongs to the Grand Complications family, it has multiple functions or complications:

  • Dual time zones
  • A leap-year cycle by hands
  • A four-digit display in an aperture
  • A 24-hour and minute subdial

For example, the Grand Complication 6300G-010 with Blue Opaline Dial has a case size of 47.7mm. Powering the 6300G-010 is the Calibre 300 GS AL 36-750 QIS FUS IRM with 108 jewels. Meanwhile, the 5374P-001 measures “just” 42mm. The 5374P-001 also includes a perpetual calendar powered by the ultra-precise Calibre R27 Q with 39 jewels.


Twenty~4 7300-1200R-001


Aquanaut Luce 5068R-010


As for the ladies' watches, those beginning with "4" tend to be the rectangular-shaped watches from the Twenty~4 collection, such as the 4910-120R-001. However, the exceptions include the Calatrava 4897, whose case is round. Round watches that spread over different collections from the Calatrava to the Twenty~4, such as the 7300-1200R-001, also begin with "7". Except for the Aquanaut Luce Line, such as the 5068R-010, and the Gondolo 5009/1J-051. Ladies' watches starting with "7" have other shapes, such as most of the elliptical timepieces in the Gondolo collection.

The Next Three Digits

The next three digits are where it gets a little complicated. The first two digits are shared by watches of similar designs in the same family. For instance, the 51xx and 52xx reference numbers have round case designs based on the Calatrava, one crown with no pushers (or another crown or two), whether they house complications, such as an annual calendar, or not. Conversely, those watches with complications are not explicitly marketed as a Calatrava. 

patek-philippe-annual-calendar-opaline-white-dial-brown-leather-mens-watch-5205r-001-876  patek-philippe-calatrava-yellow-gold-5227j-001-with-ivory-lacquered-dial-luxury-swiss-68

For example, the 5205R-001 Patek Philippe Annual Calendar Opaline with Brown Leather shares the same round case design as the Calatrava 5227J-001, but it has the annual calendar and moon-phase functions. Note the third and fourth digits, “05.” For 2021, these digits are shared with timepieces whose day of the week, date, and month are displayed at the ten, twelve, and two, respectively. Powering the 5205R-001 Annual Calendar is the Calibre 324 S QA LU 24H/303 movement with 347 parts, including 34 jewels, which provides more functionality than the Calibre 324 S C powering the Calatrava and many other Patek Philippe timepieces without complications.


Patek Philippe Aquanaut, 41mm, Stainless Steel, Black Dial


The Aquanaut seems to have its own reference number convention at first sight. However, if the reference number is 5x6x, the timepiece is probably an Aquanaut. Please note that the second digit can be a “1” or a “2,” though the Aquanaut does not share much with the Calatrava except the calibre for certain timepieces without complications. For instance, the Aquanaut 5164A-001 shares the same family of calibre as the Calatrava 5227J-001 in the form of the Calibre 324 S C with 29 jewels. The Aquanaut models with 506x model numbers belong to the ladies’ Luce collection. The Aquanaut models with more complications powered by the more intricate Calibre CH 28-520C have reference numbers at 596x. The Aquanaut Travel Time series bearing the reference number 5650 is an exception with its partly skeletonized construction around the 9 o’clock area and complications powered by the workhorse Calibre 324 S C FUS found in newly-released Calatrava models.

Patek-philippe-nautilus-5976-1g- Luxury watch

Nautilus 5976/1G

 watch patek philippe nautilus-5711-1p



Ladies' watches of the Nautilus line have reference numbers of 7x1x. If the reference number is 57xx, unless it is a 573x, in which case it is a Golden Ellipse, then it is probably a Nautilus men's watch, such as the 5711/1P. However, there are Nautilus releases, such as the 5980 and 5976/1G, that have pushers located far into the lugs. 

For 2021, the 55xx reference number is taken up by the Calatrava Pilot Travel Time with a reference number of 5524G-001 with a dual time function showing both the local and home times. 



Suppose the Patek Philippe watch has a reference number of 53xx, such as the Annual Calendar 5396R-012. In that case, it most probably has a Calatrava-based case with a single crown but counts the annual calendar and moon phase among its complications. 

To end the discussion on the second digit of the reference number, watches with a reference number of 59xx, such as the Complications Chronograph Annual Calendar 5961R-010, use the more precise CH 28-520 IRM QA and carry more complications, especially the chronograph function. 


The third and fourth digits have many “soft” rules. If a reference number ends in a “30,” such as the 5230G-010 New York 2017 Limited Edition, it is a world timer. If a reference number ends in a “96,” it usually has a Calatrava-based case with a flat bezel (unless these are Annual Calendars with a see-through sapphire case back to showcase the internal mechanism).

The Digits Following the First Four Reference Numbers

The digits and characters following the backslash (or dash), such as 5xxx/xxxx (or in the catalog on this site, “5xxx-xxx”), are more straightforward than the numbering conventions for the first four digits. In many watches, the reference number is followed by a backslash (or dash) and a different numeric code indicating the bracelet or dial type, case, and jewelry work.

  • xxxx/1 - The watch has a metal bracelet.
  • xxxx/50 - The dial is thicker than most Patek Philippe watches. These are usually enameled and gem-set.
  • xxxx/200 - The watch has a brilliant-cut gem-set case.
  • xxxx/300 - The gem-set case has baguette-cut gems.
  • xxxx/400 - The gem-set case has a high-jewelry count.
  • xxxx/500 - The case is engraved.
  • xxxx/700 - The case has gold or gem inserts. However, other materials can be used in place of gold or gems.
  • xxxx/900 - Mixed technique was used for the case and the entire watch. For instance, diamonds and enameling were used. 


These numbers after the backslash can be combined. For example, the Patek Philippe Twenty~4 Rose Gold 7300-1450R-001 means it has a metal bracelet, a high jewelry count, and an engraved case.

Following the sequence of numbers is a letter. The corresponding letters tell which material was used for the case of the watch:

  • A: Stainless Steel (Acier, in French)
  • G: White Gold
  • J: Yellow Gold
  • R: Rose Gold
  • P: Platinum
  • T: Titanium
  • PR: Platinum and Rose Gold
  • AR: Stainless Steel and Rose Gold
Patek Philippe Twenty4 Rose Gold 7300-1450R-001 with Fully paved with Diamonds dial

For example, the case material for the watch shown above is rose gold.

Lastly are three digits that follow a hyphen. These numbers refer to the dial type. Now here is where it gets complicated. There seems to be no definite pattern that the numbers follow. For instance, the last three digits followed by a hyphen “-001” range from the Gondolo, the square Twenty~4s, and the round Grand Complications. Even for the most enthusiastic Patek Philippe fans and collectors, these numbers aren’t considered important.

The Annual Calendar: How Can an Annual Calendar Model Be Identified?


Patek Philippe Complicated Annual Calendar 18kt White Gold Mens Watch 5146-1G-001


The Annual Calendar is a recent release for a Swiss luxury brand renowned for its mechanical craftsmanship and precision. The first Annual Calendar was introduced in 1996 with the reference number 5035 until the 5146 replaced it in 2005. The 5146 has been a mainstay of the Patek Philippe catalog ever since. All the Patek Philippe Annual Calendars available in retail today are powered by the Calibre 324 S QA LU introduced in 2006 and the 324 S IRM QA LU introduced in 2008. Going back further, the first Annual Calendar, the 5035, is powered by the Calibre 315/198.

Other watches that may carry the “Annual Calendar” in their brand name also have other complications such as chronographs, like in the case of 5960.

The Annual Calendar 5146 has a moon phase display, a power reserve indicator, and the day, date, and month aside from the time. Unlike the perpetual calendars, you will need to adjust the date every March 1. On the other hand, perpetual calendars won’t need adjustment until March 1, 2100, when the leap year will be skipped. Powering the 5146 is a 300-piece Calibre 324 S IRM QA LU automatic movement with a 45-hour maximum power reserve with a cyclic frequency of 28,800 per hour. Since 2008, this calibre has been powering many annual calendar models. It is the first calibre with a Pulsomax escapement, with a modified architecture made entirely of Silinvar for less power loss and more efficient power transmission.

Strictly speaking, aside from the 5146, the Annual Calendar line is composed of the watches with the reference numbers 5147, 5250, 5350, and 5450 powered by the same power source, and the 5205, 5396, and the ladies’ watch 4948, powered by its predecessor, the Calibre 324 S QA LU. 


Unlike those used for other watch brands such as Breitling or Rolex, Patek Philippe's naming convention is not as straightforward as it looks. However, the numbers' details only add to the brand’s mystique and fascination for people who wish to look deeply into each timepiece Patek Philippe creates. Each of the digits tells a story and gives an idea for the ardent admirer of the level of craftsmanship, care, and uncompromising pursuit of excellence that goes into every aspect of each Patek Philippe watch. By knowing the naming conventions, watch enthusiasts can clearly distinguish each Patek Philippe watch and family, such as the Annual Calendar, from the other collections and appreciate each timepiece's make.  Diamond Source NYC is one of the most reputable buyers and sellers of Patek Philippe watches in the country. We value the trust of our clients, and we assure that each of the timepieces we sell is certified for its authenticity. For the best shopping experience wherever you are in the world, book an appointment for a virtual shopping experience to view the Patek Philippe watches you wish to see. For more details on the availability of used or new Patek Philippe watches, call us at (212) 730-5959.