Use - Jaeger-leCoultre MASTER GRANDE TRADITION Manual

cylindrical balance-spring that guarantees an exceptional quality of timekeeping.
the perpetual calendar has a mechanism that takes into account the length of
the current month (28, 30 or 31 days), and counts 29 February every leap year.
the date, day of the week, month, year and moon phase are therefore indicated
mechanically, without the slightest need for readjustment until 1 March 2100.
all these are interlinked by an ingenious mechanism, a genuine, entirely me-
chanical programme: merely changing the initial date thus effects the appropriate
changes in all other functions.
our time measurement is based on the Gregorian calendar, i.e. a year of 365
days, 5 hours, 48 minutes and 46 seconds, or in decimals, 365.242192 days. in
practice, the yearly excess of just less than a quarter (0.242192) of a day is cor-
rected by 29 February in leap years. the few missing decimals are then compen-
sated for every 100 years, by excluding 29 February.
For the sake of greater precision, this exclusion does not take place when the
number of centuries is divisible by 4. such is the case for the years 2000 and
2400 (with centuries divisible by 4), which are regular leap years. it is therefore
only in the year 2100 that the programming of your perpetual calendar will need
to be corrected. until that date, your watch will count days, months and decades.
on 1 March 2100, the calendar will indicate Monday 29 February, whereas in
fact it will be Monday 1 March. a watchmaker will then have to set your watch
to the correct date, together with the moon phase, which varies by one day in
every 122 years.
you can use the crown of the Master Grande tradition tourbillon Cylindrique à
quantième Perpétuel watch to:
- Wind the watch if it has not been worn for more than 48 hours.
- set the desired time.

use

starting the watch
Crown in position 1.
a few clockwise turns of the crown are enough to set the watch running. it will
then automatically wind up when you wear it. Please note that the crown does
not lock during winding, even when the watch is fully wound.
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