Patek Philippe Caliber R CH 27 PS QI Mode D'emploi page 4

The minute repeater
On demand, the minute repeater strikes the
hours, the quarter-hours, and then the minutes
that have elapsed since the last quarter-hour. The
first hammer strikes the hours on the low-pitched
gong with one strike for each hour. Subsequently,
each quarter-hour is sounded as an alternating
double strike by two hammers on both the high-
and low-pitched gongs. Finally, the second hammer
strikes the high-pitched gong to count the number
of minutes that have passed since the last quarter-
hour. At 12:59, for instance, the melody consists of
12 low sounds, 3 double high/low sounds, and 14
high sounds (totaling the maximum of 32 strikes).
The chronograph
Wrist chronographs are important Patek Philippe
classics which are particularly sought after by
collectors and highly coveted at international
auctions. The Ref. 5208 is endowed with an
especially rare chronograph type in which the
three functions – start, stop, and reset – are
triggered with a single pusher; hence the name
monopusher chronograph. The minute counter is
another special feature: it runs continuously and
counts 60 minutes instead of 30 as is ordinarily
the case.
Instantaneous perpetual calendar
with aperture displays
At midnight 2 minutes, all calendar displays except
the moon phase and the day/night indicator
simultaneously and instantaneously advance to
the next day and, as the case may be, to the next
month and the next year. The perpetual calendar
automatically recognizes months with fewer than
31 days and switches directly from September 30 to
October 1 and from February 28 to March 1. In leap
years, which are indicated by the Roman numeral
IV in the aperture between 4 and 5 o'clock, the date
disk first indicates February 29 before switching to
March 1 a day later. With an annual deviation of
only 11 minutes and 47 seconds, the moon-phase
display is remarkably accurate. The error adds up
to merely one day every 122 years and 45 days. If the
watch is wound every day, the perpetual calendar
will not need to be corrected until February 28,
2100. The year 2100 is a secular year in which the
leap day is skipped according to the rules of the
Gregorian calendar.