Patek Philippe 324 S QA LU 24H/206, Manual

Page: 4 / 62

5
Introduced in 1996 and patented by Patek
Philippe, the Annual Calendar is the first timekeep-
ing mechanism that automatically displays the month,
the day of the week, and the correct date under con-
sideration of months with 30 and 31 days, so it only
has to be adjusted once a year on March 1. Its con-
struction represented a formidable challenge. To
eliminate rockers and levers to the greatest pos-
sible extent, Patek Philippe’s engineers designed
an architecture that relies mostly on wheels and
pinions. The caliber 324 S QA LU 24H movement
consists of 356 parts, whereas a conventional perpet-
ual calendar with a moon-phase display needs only
around 280 components. The calendar indications
are complemented by a 24-hour dial. Additionally,
the Annual Calendar models feature an extremely
accurate moon-phase display that deviates from the
true lunar cycle by only one day every 122 years.