Product Overview

The BBR Factory Audemars Piguet Royal Oak Perpetual Calendar 26579 features a 41mm steel case with a blue electroplated finish and a matching blue dial.

Central hour and minute hands provide the main time display. Meanwhile, calendar subdials show the date at 3 o’clock, the weekday at 9 o’clock and the month at 12 o’clock.

According to the supplied factory specifications, the display at 6 o’clock indicates day and night. A matching bracelet and folding clasp complete the blue exterior.

Technical Specifications
Specification Details
Factory BBR Factory
Collection Royal Oak Perpetual Calendar
Reference 26579
Case Diameter 41mm
Case Material Steel with blue electroplated finish
Bezel Steel with blue electroplated finish
Dial Colour Blue
Crystal Sapphire crystal with anti-reflective coating
Movement Factory-described C5134 automatic mechanical movement
Main Time Display Central hours and minutes
Additional Central Hand Factory-described calendar-cycle hand; exact function requires confirmation
Date Display Positioned at 3 o’clock
Day/Night Display Positioned at 6 o’clock, according to factory specifications
Weekday Display Positioned at 9 o’clock
Month Display Positioned at 12 o’clock
Perpetual Calendar Operation Not confirmed
Bracelet Steel with blue electroplated finish
Clasp Folding clasp with blue electroplated finish
Water Resistance Factory-stated 50 metres; not independently verified
Quality Control Movement, calendar displays and exterior inspection before shipment
Movement and Functions

The factory lists a C5134 automatic mechanical movement for this version. Its supplied functions include timekeeping, calendar displays and a day/night indicator.

However, the movement designation does not establish the same construction or calendar capability as the genuine Audemars Piguet calibre. In particular, automatic correction for different month lengths and leap years remains unconfirmed.

Central Hour and Minute Hands

The shorter central hand displays the hour, while the longer hand indicates the minutes.

Together, they provide the watch’s main time display.

Additional Central Calendar Hand

The factory describes an additional central hand as a “calendar-cycle hand.”

Its exact purpose needs confirmation through the dial markings and a functional demonstration. Therefore, this page does not label it as a working week-number or leap-year indicator.

Calendar Displays
Date Display at 3 O’clock

The right-hand subdial displays the numerical date.

However, the supplied information does not confirm whether the mechanism automatically corrects the date after shorter months.

Day/Night Display at 6 O’clock

The factory identifies the lower display as a day/night indicator.

This description follows the supplied specifications. It does not confirm a working astronomical moon-phase function.

Weekday Display at 9 O’clock

The left-hand subdial displays the day of the week.

Alongside the date display, it provides a convenient calendar reference.

Month Display at 12 O’clock

The upper subdial displays the month.

However, the factory has not confirmed an additional leap-year function or its operation.

Case and Dial

The 41mm case uses steel with a blue electroplated finish. The matching bezel extends the colour across the exterior, while the blue dial completes the coordinated appearance.

Multiple subdials give the watch a detailed calendar layout. Meanwhile, the central hour and minute hands keep the main time display separate from these additional indications.

A sapphire crystal protects the dial. In addition, its anti-reflective coating helps reduce glare.

Bracelet and Clasp

The bracelet uses steel with a matching blue electroplated finish. A folding clasp secures it around the wrist and continues the same colour scheme.

Because the blue colour comes from a surface finish, avoid abrasive polishing. Also, keep the bracelet away from harsh cleaning chemicals that could affect the coating.

Calendar Adjustment

Calendar movements can require a specific adjustment sequence. Therefore, follow the operating instructions for the actual BBR movement when setting the date, weekday and month.

Do not force the crown or calendar correctors. If a control feels resistant, stop and request guidance before continuing.

Water Resistance

The factory states 50 metres of water resistance. However, no independent pressure-test report confirms the individual watch’s performance.

Avoid swimming, showering and immersion without an appropriate pressure test. In addition, do not operate the crown or calendar correctors while the watch is wet.

Care Instructions
Clean the case and bracelet with a soft microfibre cloth.
Avoid abrasive polishing on the blue electroplated surfaces.
Keep the watch away from strong magnets and heavy impacts.
Follow the correct calendar-setting procedure.
Do not force the crown or calendar controls.
Close the folding clasp fully before wearing the watch.
Arrange an inspection if the calendar displays stop advancing or behave unusually.
Frequently Asked Questions
What is the case diameter?

The factory lists a case diameter of 41mm.

Is the case made from blue ceramic?

The supplied specifications describe steel with a blue electroplated finish. They do not list ceramic as the case material.

What movement does this version use?

The factory identifies the movement as a C5134 automatic mechanical movement. Its internal construction and full calendar capabilities require confirmation.

Does it have a fully functioning perpetual calendar?

The supplied information does not establish automatic correction for month lengths and leap years. Therefore, the collection name should not serve as a guarantee of full perpetual calendar operation.

What does the display at 6 o’clock show?

According to the factory specifications, it shows day and night. A working moon-phase function has not been confirmed.

What does the additional central hand show?

The factory calls it a calendar-cycle hand. Actual dial markings and a functional demonstration are needed to identify its exact purpose.

Where are the calendar displays?

The date sits at 3 o’clock, the weekday at 9 o’clock and the month at 12 o’clock.

Will you inspect the watch before shipment?

Yes. Our team will inspect the movement, calendar displays, exterior finish and clasp after the watch arrives from the factory.

We will then provide two QC videos showing movement operation and the actual watch. Finally, we will confirm the model and delivery details before shipment.