To celebrate the 75th anniversary of the birth of an iconic watch —the IWC Portuguese— IWC continues to enhance its Portugieser watch family with new eye-catching complications. After the minute repeater in 1995, the 7-day power reserve in 2000, the perpetual calendar in 2003, the Tourbillon Mystère in 2004, the constant-force tourbillon in 2011 and the recent 8-day hand-wound movement presented in 2013, consolidated the Portugieser watches’ reputation as one of the leading lights of haute horlogerie. In 2015, the Year of the Portugieser, IWC’s newly developed annual calendar is another interesting additional feature to complement the perpetual calendar. The complication is powered by the new IWC in-house 52850 calibre. Both are found for the first time in the Portugieser 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, semicircular 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 designer sensured 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 Portugieser Annual Calendar’s purist design. 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.

For technology buffs, here's a brief explanation of the way the annual calendar function works. 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 Portugieser 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.

With its voluminous 44.2 mm case, grooved bezel, classic railway-track-style chapter ring, slim feuille hands and almost unchanged Arabic numerals, the Portugieser Annual Calendar very closely resembles the original Portugieser 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 Portugieser 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.

The Portugieser Annual Calendar is available in 18K red gold as 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 sunray finish on the blue dial reflects incident light dynamically 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. 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 development 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 run time.

Sticker Price $24,100 USD for Stainless Steel and $34,500 USD for 18K red gold. For more info on IWC Schaffhausen click here.