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The Encyclopedia of Horology

Wristwatch · Annual Calendar Flyback Chronograph

Patek Philippe Annual Calendar Flyback Chronograph 5905/1A-001

Partially verified

This Patek Philippe wristwatch, reference 5905/1A-001, is a complex mechanical timekeeper featuring both an annual calendar and a flyback chronograph. The watch is powered by the automatic Calibre CH 28-520 QA 24H, which is visible through a sapphire crystal case back. Housed in a 42 mm stainless steel case, the design includes a signed crown and square pushers, matched with a stainless steel bracelet. The green dial features applied indices, white minute tracks, and luminescent obelisk hands, with apertures for day, date, and month, alongside a sub-dial at the six o'clock position for the chronograph seconds. The annual calendar mechanism is designed to account for varying month lengths, requiring manual adjustment once a year at the end of February. The watch is presented as being complete with all factory accessories and is attributed to production in the 2020s.

Front view of the Patek Philippe Annual Calendar Flyback Chronograph 5905/1A-001 showing the green dial and steel bracelet.
Front view of the Patek Philippe Annual Calendar Flyback Chronograph 5905/1A-001 showing the green dial and steel bracelet. — Zamanito. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
zamanito.com
Category
Wristwatch · Annual Calendar Flyback Chronograph
Maker / attribution
Patek Philippe
Reference
5905/1A-001
Catalogue / lot identifier
Source URL identifies the listing
Source-reported date
2020s
Source-reported place
Switzerland

Source-reported attribution and specifications are not independent authentication. A listing does not establish present ownership, current display, availability or permission to reproduce.

Object description

Case and Dial Design

The timepiece is encased in a 42 mm stainless steel housing, finished with a polished concave bezel. It features a notable green dial, which acts as a backdrop for applied indices and luminous obelisk-style hands. The dial layout provides data for the annual calendar via three apertures placed horizontally across the upper section of the face, indicating the day, date, and month.

In addition to the time and calendar functions, the dial incorporates a sub-dial situated at the six o'clock position, which serves as the chronograph's running seconds. A white minute track encircles the outer edge of the dial, and the watch is completed with a steel bracelet. The case back is fitted with a sapphire crystal viewing window, allowing for observation of the internal mechanism.

Evidence for this section
  • “بدنه این ساعت از فولاد ضد زنگ ساخته شده و دارای قطر ۴۲ میلی‌متر است”
  • “صفحه ساعت به رنگ سبز چشم‌گیر است و شامل شاخص‌های اعمال شده، مسیر دقیقه‌شمار سفید و عقربه‌های obelisk شب‌نما می‌باشد”
  • “در پشت ساعت، یک قاب نمایشگر از جنس یاقوت کبود وجود دارد”

Movement and Complications

The watch utilizes the automatic Patek Philippe Calibre CH 28-520 QA 24H movement. This movement integrates two distinct functions: an annual calendar and a flyback chronograph. The annual calendar is a technical feature developed by the brand that automatically adjusts for months with 30 or 31 days, necessitating a single manual correction per year at the end of February.

The inclusion of the flyback chronograph allows the user to stop, reset, and start the chronograph function instantly using a single pusher.

Evidence for this section
  • “موتور اتوماتیک Patek Philippe Calibre CH 28-520 QA 24H را به نمایش می‌گذارد”
  • “تقویم سالانه که توسط پاتک فیلیپ اختراع شده، قادر است ماه‌های با طول متفاوت را تشخیص دهد و تنها یک بار در سال، در پایان ماه فوریه، نیاز به تنظیم دستی دارد”
  • “کرنوگراف فلای‌بک که امکان توقف و شروع مجدد آنی را با یک دکمه فراهم می‌کند”

Provenance and Accessories

According to the source documentation, the watch is supplied with all original factory accessories. It is considered a representative example of the brand’s production during the 2020s, combining technical complexity with stainless steel construction.

The information provided serves as a catalogue record based on the secondary market listing.

Evidence for this section
  • “ساعت مذکور همراه با تمامی متعلقات کارخانه‌ای عرضه می‌شود”
  • “این ساعت یک نمونه برجسته از ترکیب پیچیدگی‌های کاربردی در یک بدنه فولادی است که در دهه ۲۰۲۰ تولید شده”
  • “این اطلاعات و سابقه به منبع نسبت داده می‌شوند”

Open research questions

  • What is the specific production year of this individual watch within the 2020s?
  • Does the serial number on the case match the documentation provided in the factory set?

Source evidence

Recorded claims and source quotations for Patek Philippe Annual Calendar Flyback Chronograph 5905/1A-001
FieldSource-reported valueSource quotation
MakerPatek Philippe“Patek Philippe”
Reference5905/1A-001“5905/1A-001”
Case MaterialStainless steel“فولاد ضد زنگ”
Case Diameter42 mm“۴۲ میلی‌متر”
MovementCalibre CH 28-520 QA 24H“Patek Philippe Calibre CH 28-520 QA 24H”
Production Period2020s“دهه ۲۰۲۰”

Visible details

  • Signed winding crown
  • Three calendar apertures at top of dial
  • Chronograph sub-dial at 6 o'clock
  • Square chronograph push-pieces

Research qualifications

  • Movement condition not verified by the source
  • Exact production year within the 2020s not specified

Photograph identity and source facts were screened before import; rights clearance remains pending.

Terms in this record

Glossary explanations for terms named in this object’s record.