Timepieces that will be passed down forever #20 Zenith Chronomaster Original Triple Calendar

Zenith's latest creation, the Chronomaster Original Triple Calendar Aventurine, is based on a legendary model of which 25 prototypes were made in 1970. Equipped with the latest version of the legendary automatic chronograph, the El Primero, in a round case, the origin of timepieces, this model is a legitimate evolution created over half a century.

Technology that should be woven into the next generation as seen in the lineage of legendary chronograph watches

　The El Primero, an integrated automatic chronograph movement released in 1969, is not only equipped with a high-precision escapement that operates at a high beat of 36,000 vibrations per hour, but from the very beginning of its development it was also equipped with a triple calendar display function (month, day of the week, and date), as well as a moon phase indicator function that shows the phases of the moon.

　While much of the discussion surrounding the automatic chronograph development race of the late 60s has focused on the timing of announcements and releases, the Zenith El Primero incorporated forward-thinking design concepts from the very beginning of its development. This is a little-known but undeniable fact.

　Based on this advanced design concept, only 25 prototypes were produced in 70. These were prototypes with a basic round case, an El Primero with a triple calendar and moon phase display.

　However, this model was never put into production, and a few years later, the triple calendar El Primero was released as a model with a massive, angular case called the "Space Age," which met the needs of the time.

　Now, more than half a century later, a round-case triple calendar moon phase model equipped with the masterpiece automatic chronograph movement El Primero has made a spectacular comeback. It can be said to be an evolved version of the legendary El Primero, which is descended from the A386 released in 69.

　Furthermore, this new triple calendar moon phase model has been released as a limited edition model exclusively for the Japanese market, with two models: an aventurine model with a beautiful sparkle on the dial, and a malachite model with a vibrant green striped pattern on the dial.

　The compact 38mm stainless steel case of this Japan-exclusive model is full of vintage charm and was designed based on the blueprints and proportions of the A386. This case does away with the bezel and instead has a classic domed sapphire crystal set directly into the case, successfully combining a clean look with a nostalgic atmosphere.

　Needless to say, the movement used is the El Primero 3610, the latest version of the legendary high-beat automatic chronograph movement.In addition to a highly accurate chronograph mechanism capable of measuring time to 1/10 of a second, it is a complication that incorporates a triple calendar displaying the month, day of the week, and date, as well as a moon phase indicator.

　Despite its complex display mechanism, the dial is particularly elegant and easy to read. The month window is located above the 60-second counter at 3 o'clock, and the day of the week window is located above the small seconds at 9 o'clock.

　In keeping with Zenith tradition, the date window is discreetly placed between the 4 and 5 o'clock indices, and the 60-minute counter and moon phase display are coaxially mounted on the subdial at 6 o'clock. This is a truly rational, streamlined display layout with excellent visibility.

　The El Primero 3610 movement boasts a long power reserve of approximately 60 hours thanks to its efficient transmission mechanism, despite being equipped with such a complex mechanism. The see-through case back allows visitors to appreciate the exquisite finish of this masterpiece chronograph movement, which deserves to be remembered for its history, including the blued column wheel, which is said to be essential for high-end chronographs, and the automatic winding rotor cut out with Zenith's symbolic star. This is truly a new masterpiece that inherits and develops the legend.