Patek Philippe Annual Calendar Chronograph

After it was launched in January 2006, the Annual Calendar Chronograph Ref. 5960 instantly became a bestseller among Patek Philippe's complications. With its patented Annual Calendar and Patek Philippe's proprietary self-winding chronograph movement, it offers functions that are very useful in everyday situations. Now, this technical opus, previously available only in platinum, also comes in a case made of 18K rose gold.

The CH 28-520 IRM QA 24H manufacture caliber: Tradition and innovation hand in hand
Developed and manufactured in-house, the self-winding CH 28-520 IRM QA 24H chronograph caliber addressed an expectation long harbored by many aficionados and collectors of Patek Philippe timepieces. In addition to the normal time indication, the movement stands out with numerous features. It has a flyback column-wheel chronograph, a power-reserve indicator, an Annual Calendar with day, date, and month, and a day/night indicator. Beating at 28,800 semi-oscillations per hour (4 hertz), it maintains an extremely constant balance amplitude and high rate accuracy. The winding power is generated by a unidirectional central rotor in solid 21K gold.

With its classic column wheel and a vertical disk clutch, the movement combines the traditional chronograph control concept with a modern power transmission solution. It offers high functional reliability and eliminates the danger of hand bounce when the chronograph is activated. Because of its low-wear design and the absence of any negative influence on the rate accuracy of the watch, the chronograph hand can be used as a continuously running seconds hand without hesitation.

The patented Patek Philippe Annual Calendar is a full-function calendar that automatically recognizes months with 30 and 31 days and when kept running only needs to be corrected by hand once a year on March 1. It displays the day, date, and month in three apertures and controls the day/night indicator at 6 o'clock.

A new look in 18K rose gold
The new rose gold case adds an attractive and contemporary touch of nostalgia to this impressive instrument. The same warm hue of 18K rose gold ennobles the luminescent hands, the applied hour markers, and the polished frame of the date aperture. They contrast well with the dark silvery gray of the vertically satin-finished dial that in its bottom half showcases the brighter zone of the delicately snailed minute and hour counter. On three concentric scales, it indicates elapsed minutes and hours while the chronograph is running. On the two outer scales, the longer red hand counts the minutes from 0 to 30 (red numerals) and from 30 to 60 (blue numerals) while the shorter blue hand keeps track of as many as 12 elapsed hours along the innermost scale.

The day/night (am/pm) indication is a small round aperture that progressively changes its color from white (day) to dark blue (night) and vice-versa. This function is also significant when the time and calendar indications need to be readjusted after a longer standstill period and an am/pm differentiation is required.

The day, date, and month apertures are arranged along an arc at the upper periphery of the dial. The date at 12 o'clock is particularly prominent, forming a visual balance with the monocounter that dominates the bottom half of the dial. The small power-reserve indicator hand beneath the date aperture moves between the plus and minus signs to indicate the state of wind of the mainspring.

With a diameter of 40.5 millimeters, the Ref. 5960R Annual Calendar Chronograph is a stately timepiece without violating the rules that apply to timelessly elegant watches. It is worn on a brown large-scaled alligator strap with an 18K rose gold clasp that assures a snug and secure fit on the wrist.