iwc PORTUGIESER PERPETUAL CALENDAR TOURBILLON Operating Instructions Manual page 12

— 1 2 —
However, it is better to wind the watch
to approximately the 3­day marking on
the power reserve as this will ensure
optimal accuracy. The crown must
always be in position 0 when you are
wearing your watch.
S E T T I N G T H E T I M E
A N D C A L E N DA R
If you have not worn your watch for
more than 7 days, the power reserve
display will go back to 0 and the watch
will normally stop at midnight, as the
changeover of the calendar uses
a great deal of energy.
P O R T U G I E S E R P E R P E T U A L C A L E N D A R T O U R B I L L O N