Patek Philippe Annual Calendar Chronograph
One of the most useful combinations of complications is what we get in the new “Patek Philippe Annual Calendar Chronograph”. This is not a complete first since it had been made previously available in rose gold with a chocolate dial or in platinum with a blue or black dial. But this latest release comes in steel with a 3-link bracelet, making it a unique sporty option in the Patek Philippe collection.
The 42mm case is made of stainless-steel with a polished finish, while mounted to the case is a convex bezel.
On the flip-side is an exhibition case back, which allows us to view the inner workings of the mechanical movement. Among several moving parts and jewels in full display is also an 18k gold oscillating weight with the Patek Philippe calatrava insignia.
It comes equipped with rectangular pushers to operate the chronograph functions and a setting-crown in between also decorated by an embossed engraving of the calatrava cross.
While along the left-side of the case are the discreet corrector pushers that serve to adjust the annual calendar. 
The patented Annual Calendar automatically can take into account 30 and 31-day months, requiring only one correction per year, on March 1st. Water-resistance on this watch can reach up to 30 meters (98 feet). 
Time is exhibited on an olive green sunburst dial with 18k white gold applied hour index markers, followed by a ring of small white minute index markers circling along the flange.
On the upper-half are three windows that showcase the annual calendar function in a European layout of: weekday, date, and month.
While on the lower-half is a large sub-seconds dial, which also doubles as a 60-minute counter for the chronograph.
A small round aperture in the sub-counter is used as a day-night indicator.
The central hours/seconds hands made of 18k white gold (just like the hour index markers) have all been fitted with a luminescent coating, for an enhanced legibility.
Patek Philippe Annual Calendar Chronograph
The “Patek Philippe Annual Calendar Chronograph” (Ref#: 5905/1A-001) is powered by the self-winding in-house mechanical movement, caliber CH 28-520 QA 24H with 37 jewels, 402 components and 28,800 Vph. It comes equipped with an integrated automatic flyback chronograph with column-wheel and annual calendar module. Power reserve on this timepiece can last up to 45-55 hours, when fully wound.
Mounted to the watch is a 3-link polished stainless-steel bracelet, secured to the wrist by a fold-over clasp. 
For more up to date information visit the official Patek Philippe website here.
