IWC Portugaise Calendrier Annuel IW503504

PORTUGUESE ANNUAL CALENDAR

The new Portuguese Annual Calendar brings together two firsts for IWC and three masterstrokes of haute horlogerie in a single case: the newly developed annual calendar closes the gap between the perpetual calendar and the simple date display. The new IWC-manufactured 52850 calibre has two barrels that keep the new function supplied with ample energy and still has enough left for a 7-day power reserve.

IWC continues to enhance its Portuguese watch family with new, eye-catching complications. After the minute repeater
(1995), the 7-day power reserve (2000), the perpetual calendar  (2003), the Tourbillon Mystère (2004) and the
constant-force tourbillon (2011) – to name but a few – the recent 8-day hand-wound movement (2013) consolidated
the Portuguese watches’ reputation as one of the leading lights of haute horlogerie.

In 2015, the Year of the Portuguese, IWC’s newly developed  annual calendar is another interesting additional feature to
complement the perpetual calendar. The complication is powered by the new IWC-manufactured 52850 calibre.
Both are found for the first time in the Portuguese Annual Calendar (Ref. 5035). The watch thus symbolizes the
launch of an IWC initiative to produce further series of in-house calibre families in the years ahead.

Located at “12 o’clock” on the dial, IWC’s annual calendar shows the month, date and day in three separate, semi-
circular windows. The switching mechanism automatically takes into account the differing lengths of individual months.
Unlike a perpetual calendar, however, the annual calendar is unable to factor in the differing length of the month of
February or the leap years. Once a year, then, at the end of February, it requires manual correction. For the development of the annual calendar module, IWC’s watch designers  ensured that the correction could be carried out easily and
conveniently using the crown. Thanks to this elegant solution, the engineers were able to dispense with a corrector,
which would have compromised the Portuguese Annual Calendar’s purist design.

IN THE STYLE OF A DESIGN ICON

In order to free up as much space as possible for the date display, the designers replaced the indices from “11 o’clock” to “1 o’clock” with the three display discs. The “American” order in which the date is shown was not only necessary from a technical and design point of view, but is also a homage to F. A. Jones, IWC’s American founder. With its voluminous 44.2-millimetre case, grooved bezel, classic railway-track-style chapter ring, slim feuille hands and almost unchanged Arabic numerals, the Portuguese Annual Calendar very closely resembles the original Portuguese of 1939, a veritable design icon. The small seconds subdial, however, is not positioned at “6 o’clock” as in the original, but at “9 o’clock”. The subdial on the opposite side contains the power reserve display. The in-house movement with 7-day power reserve is yet another quantum leap in the history of the Portuguese family. The rare combination of an annual calendar and 168-hour calibre should make this latest complication from the House of IWC even more attractive for watch connoisseurs.

FASCINATING INSIGHT INTO THE NEW IWC-MANUFACTURED MOVEMENT

The Portuguese Annual Calendar is available in 18-carat red gold (Ref. IW503504) with a silver-plated dial or in
stainless steel with a silver-plated (Ref. IW503501) or midnight blue (Ref. IW503502) dial. The fine sun-pattern  finish
on the blue dial reflects incident light dynam i cally in a myriad directions. All versions of the watch are fitted with black
Santoni alligator leather straps. The arched-edge sapphire glass makes the case look slimmer and underscores the
watch’s classic elegance. The curved strap horns ensure greater comfort even on slimmer wrists. The see-through
sapphire-glass back provides an unimpeded view of the exquisite new IWC-manufactured 52850 calibre. Across
the entire 52000-calibre family, the rotors have been made slimmer, while the bridges are more open and inset with a
solid gold “Probus Scafusia” medallion. This way, even more details of the movement with its two barrels can be seen.
The improved Pellaton winding system with the practically wear-free components made of black and white ceramic
is also clearly visible.

5 YEARS IN DEVELOPMENT

Overall, it took IWC’s watch designers almost 5 years to develop the annual calendar. Whereas they had been able
to draw on in-house experience when developing the perpetual calendar, this was not the case during the develop ment of the annual calendar. The new in-house 52850 calibre is the perfect choice for the annual calendar because it has two barrels to provide the higher torque required to drive the three display discs. In addition, when fully wound, the twin barrels supply enough energy for a full week’s runtime.

For technology buffs, a brief explanation of the way the annual calendar functions: the hour wheel sets in motion
the date advance wheel, which is equipped with two different advance fingers. One of the fingers is responsible for
the date and month displays, the other for the weekday display. Every day, towards midnight, the date is moved
forward with the help of the upper advance finger. The month display and the programme wheel, which defines
the lengths of the various months, are controlled by two pins on the date disc. The first of these pins advances the
programme wheel by one division. A feeler on the advance lever recognizes months with 30 days by a deeper notch
on the program  wheel and provides more space for it to switch. The following day, the advance lever ensures that
the date moves forward by 2 days. The second pin in the date disc sets the new month.

The 5 years’ development time for the annual calendar was worth the effort. With the Portuguese Annual Calendar, IWC Schaffhausen has given yet another demonstration of its ability to innovate, to expand its in-house watchmaking expertise, and in the process, to extend the repertoire of IWC complications by another attractive and practical
additional function.