Patek Philippe GENEVE 324 S QR Manual De Instrucciones página 5

A perpetual calendar with a retrograde date hand
is a rare combination presented in an unusual lay-
out. Instead of sweeping a full circle, the date hand
jumps back to the beginning of its arc 24 hours after
reaching the last day of the month. It advances day
by day until it indicates the 28 , 29 , 30 , or 31 of
th th th st
the month (depending on the current month and leap
year cycle) and subsequently returns to the 1 day
st
of the month. A spiral spring is used to perform
this instant retrograde motion of the date hand. The
ingenious mechanism developed by Patek Philippe
does not absorb any energy from the mainspring
barrel and prevents the date hand from bouncing
forward to the 2 or 3 day of the month when the
nd rd
retrograde motion takes place. In contrast to other
Patek Philippe watches with perpetual calendars,
the perpetual calendar with a retrograde date hand
is based on the self-winding caliber 324 movement
with a central rotor. This ranks it among the rare
perpetual calendars with a sweep seconds hand. The
moon phase display is extremely accurate and devi-
ates from the true lunar cycle by only 11 minutes and
47 seconds per year. The deviation adds up to merely
one day in 122 years and 45 days. If the watch is
worn daily, the perpetual calendar will not have to
be corrected until February 28, 2100. This is known
as a secular year, which – as an exception – omits
February 29.
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