Perpetual Calendar

      Perpetual Calendar is a highly complex automatic mechanism with a perpetual calendar function that displays the day, date, moon phases (Moon phases), and year. It can accurately display the date according to the month—accounting for 30-day and 31-day months, and even correctly adjusting for February based on the year.

In this article, we will introduce you to several watches equipped with a Perpetual Calendar system. 

A. Lange & Sohne 1815 Rattrapante Perpetual Calendar

     The 1815 Rattrapante Perpetual Calendar combines two classic complications: a Rattrapante chronograph and a perpetual calendar, complete with a moon phase display. It is easily one of the most beautifully and meticulously designed timepieces from any brand.

Watch Specifications

• Brand: A.Lange & Sohne
• Family : 1815
• Timepiece : 1815 Rattrapante Perpetual Calendar
• Reference : 421.032
• Calibre : L101.1
• Case : pink gold
• Dial : solid silver, argenté
• Hands : pink gold, blued steel
• Case Measurements Diameter : 41.9 mm; height: 14.7 mm

Audemars Piguet Royal Oak Perpetual Calendar

     While the brand has a long history of watchmaking, the Audemars Piguet Royal Oak Perpetual Calendar perfectly balances the brand's iconic design language with the sophisticated Perpetual Calendar system.

Watch Specifications

• Brand: Audemars Piguet
• Family: Royal Oak
• Reference: 26585CE.OO.1225CE.01
• Name: Royal Oak Perpetual Calendar Openworked 41 Ceramic / Slate

Case

• Materials: Titanium, Ceramic
• Glass: Sapphire
• Back: Open
• Shape: Other
• Diameter: 41.00 mm
• Height: 9.90 mm
• W/R: 20.00 m

Dial

• Color: Skeleton
• Indexes: Stick / Dot
• Hands: Stick

IWC Portugieser Perpetual Calendar

     The IWC perpetual calendar displays the date, day of the week, month, moon phases, and year as a four-digit number, functioning with perfect precision until the year 2499. Developed by Kurt Klaus in the early 1980s and debuted in the iconic Da Vinci Perpetual Calendar in 1985, this ingenious mechanism was developed under the code name "Operation Eternity." It propelled IWC to the pinnacle of haute horlogerie and remains a milestone in the art of watchmaking to this day. Over the years, IWC engineers have continuously refined the original mechanism, developing perpetual calendar watches with features like digital displays for the month and day, or double moon phase displays.

Watch Specifications

• Brand: IWC
• Family: Portugieser
• Reference: IW5033-01 (aka: IW503301)
• Name: Portugieser Perpetual Calendar Single Moon White Gold / Ardoise

• Material: White gold
• Glass: Sapphire
• Back: Open
• Shape: Round
• Diameter: 44.20 mm
• Height: 15.30 mm
• Lug Width: 22.00 mm
• W/R: 30.00 m

Dial

• Nickname: Ardiose
• Color: Grey
• Indexes: Arabic Numerals
• Hands: Feuille

Jaeger Lecoultre Master Ultra Thin Perpetual Pink Gold

     JLC has long been dedicated to developing the thinnest watch cases possible. Notably, the Jaeger-LeCoultre Master Ultra-Thin Squelette (3.60 mm) surpassed the Piaget Altiplano 900P (3.65 mm) by 0.05 mm, solidifying JLC’s position as the brand holding the record for the thinnest watch currently. Beyond the brand's excellence, complex mechanics, and beautiful finishing, here is a fun fact: Doctor Strange from the Marvel Cinematic Universe wears this very JLC model.

Watch Specifications

• Brand: Jaeger-LeCoultre
• Family: Master
• Reference: 1302520 (aka: Q1302520)
• Name: Master Ultra Thin Perpetual Pink Gold / Eggshell / Alligator 

Case

• Material: Pink gold
• Glass: Sapphire
• Back: Open
• Shape: Round
• Diameter: 39.00 mm
• Height: 9.20 mm
• W/R: 50.00 m

Dial

• Nickname: Eggshell
• Color: Beige
• Finish: Matte
• Indexes: Stick / Dot
• Hands: Dauphine

Patek Philippe Nautilus 5740/1G 

     As the first Grand Complication in the Nautilus collection, the 5740/1 Nautilus Perpetual Calendar features a striking blend of sporty appeal and technical complexity. Powered by the famous, ultra-thin Calibre 240 Q movement, the case (water-resistant to 60 m) is stunningly beautiful, making this the thinnest Patek Philippe watch. The bracelet comes equipped with a new, secure fold-over clasp.

Watch Specifications

• Brand: Patek Philippe
• Family: Nautilus
• Reference: 5740/1G-001
• Name: Nautilus Perpetual Calendar 5740 White Gold / Blue 

Case

Dial

• Color: Blue
• Indexes: Stick / Dot
• Hands: Stick

Vacheron Constantin Overseas Perpetual Calendar Ultra-Thin

     The Overseas collection has always had a distinct identity, perhaps because it was not designed by Gérald Genta. This version of the Overseas QP stands out from its predecessor with its new movement design and openworking, a clever approach that gives it a highly unique character.

Watch Specifications

• Brand: Vacheron Constantin
• CASE Material : 18K 5N pink gold
• Size (mm) : 41.5 mm
• Thickness (mm) : 8.10
• Caseback : Transparent caseback, sapphire glass
• Water-resistance (bar) : 5
• Specifities : Anti-magnetism
• BRACELET : Number of bracelets 2
• Material of the bracelets : 
• Mississippiensis alligator (dark blue), rubber (dark blue)
• Size : 23.60/20
• BUCKLE Type : Deployant buckle
• Material : Pink gold
• Reference : 1120 QP/1
• Energy : Self-winding
• Size (mm) : 29.60 (12½''')
• Thickness (mm) : 4.05
• Number of parts : 276
• Number of jewels : 36
• Power reserve (hours) : 40
• Frequency : 19800 v.p.h. (2.75 Hz)