iwc PORTUGIESER PERPETUAL CALENDAR Mode D'emploi page 24

Crossing time zones and the Date Line with the
Portuguese Perpetual Calendar
Setting when crossing time zones:
• When crossing time zones in an easterly direction, you should simply set
the time forward to the new local time.
• If you cross time zones in a westerly direction, you can set the hands of
your watch back to the actual time of day. When doing this, however, you
must not move back into the calendar's automatic switching phase, i.e.
beyond 2 am. If this situation occurs when you are travelling west, you
should set the local time of your destination before 8 pm. You must not
turn the hands back between 8 pm and 2 am.