At the heart of the calibre PF317, the cam which governs the months is equipped with a planet gear which controls the variable number of days in February. The indication for this device is released from the central wheel at the right point in time, jumping the date instantly to the first of the next month. This type of mechanism is highly complex to create on the minute scale of a wristwatch.
The device governing the precision moon calendar is integrated into the same module as the date calendar. By virtue of its gear system, which is much more complex than on a conventional lunar calendar, it tracks the moon phases accurately, with only one correction needed every 122 years.
The distinguishing feature of the Toric Quantième Perpétuel Rétrograde is its two dial versions which offset the red gold of the case. The first is white grained, which uses expertise specific to the Parmigiani Fleurier manufacture to lend the material a striking brilliance. The second dial has a hand guilloché finish, with a pattern representing the concentric arrangement of the scales on a pine cone. This arrangement is one of many natural expressions of the Golden Ratio which defines a harmonious relationship of proportions.
The calibre PF333 is a self-winding mechanical movement. Its two series-coupled barrels ensure excellent rate regularity and a power reserve of 50 hours. An additional module governs the calendars: both the date and moon calendars. The calibre PF333 is decorated to the highest Haute Horlogerie standards, with superbly bevelled and circular-grained main plate and bridges, both featuring Côtes de Genève decoration. Its gold oscillating weight is delicately engraved and stamped with the initials PF.
