IWC Schaffhausen PORTUGIESER PERPETUAL CALENDAR Mode D'emploi page 25

Power reserve display
The power reserve display is divided into 7 days with continuous display. The
winding mechanism winds the watch continuously while you are wearing it,
and you can follow the process on the power reserve display. Depending on
your model, the marking which may be present in the area of the last day tells
you that the power reserve is about to expire. You should then wind the watch
by hand, if necessary, since the precision can be reduced in this area.
Moon phase display
1
Full moon
The moon phase display shows the moon in the northern hemisphere in the
upper half and the moon in the southern hemisphere in the lower half and is
automatically set by the calendar so that it is always correct. The transmission
ratio is so precise that the display deviates by only a single day after 577 years.
Countdown display
which are represented as 29.5 days on the rotating moon phase display, in
conjunction with the extremely precise perpetual calendar.
2
Waning moon
The arrows to the left and right of the moon phase dis-
play are used to indicate the days remaining until the
next full moon. The period that elapses between one full
moon and the next is always exactly 29.530588402 days,
3
New moon Waxing moon
20 | 21
4