Reference 3974 – The two complications in which Patek Philippe excels – the perpetual calendar and the minute repeater – come together for the first time in a wristwatch with a self-winding movement.
The dial has the traditional layout of Patek Philippe’s well loved perpetual calendars, showing the day, date, month, leap year and the 23 hours
with remarkable carity.
The only aperture in the dial is for the moon phases.
The perpetual calendar is known for its unfailing reliability as it follows the different sequences of long and short months, combining them with the different cycles of leap years, and lunations; dividing the day both into 24 hours and into 12 hours. This beautifully engineered instrument is the pride of Patek Philippe’s watchmakers.
Buried in the 467 parts of the movement is the intricacy of cams and racks that converts the time on the dial into the time you can hear. Patek Philippe’s minute repeaters strike the hours, quarters and minutes on two gongs of special acoustic steel to give a sharp, clear time. The spinning governor which regulates the tempo of the strike is totally silent.
Dial indications – Month and year at 3 o’clock, date and moon phases at 6 o’clock. Day and am/pm indicators at 9 o’clock.
Specifications of the movement:
Overall diameter: 28mm
Number of parts: 467
Number of jewels: 39
Power reserve: 48 hours max.
Winding rotor: 22 karat gold mini-rotor, unidirectional winding
Frequency: 21,600 vibrations/hour
Balance spring: Flat
Hallmark: The Geneva Seal