iwc AQUATIMER AUTOMATIC 2000 Operating Instructions Manual page 10

Time setting
Pull out the crown to position 2. This will stop the
movement. To set the time accurately to the second, it
is best to stop the movement as the seconds hand
reaches 60. You can now set the time by turning the
crown and positioning the minute hand exactly above
the minute stroke. To start the seconds hand, push
in the crown to position 0. When setting the time, please
be aware of the date change, which always takes
place at 12 midnight. If this change has already taken
place at 12 noon, you must move the hands forward
by 12 hours.
Important: Although the watch is water-resistant in
positions 0, 1 and 2, the crown must always be screwed
in again for normal use (position X).
Reading the time in the dark
The dial, the hour and minute hands as well as the
marking on the rotating bezel of your watch have
luminescent elements that allow you to read the time
effortlessly even in total darkness. The two luminescent
elements at 12 o'clock serve as a reference point.