iwc IW376501 Mode D'emploi page 21

Reading the time in the dark 18 | 19
Both the dial and the hour and minute hands of your watch have luminescent
elements that allow you to read the time effortlessly, even in total darkness.
Reading the double chronograph
Chronograph seconds hand and split-seconds hand: The scale for the
central chronograph seconds hand and the central split-seconds hand runs
around the edge of the dial.
Minute counter: The 30-minute scale with a slow jumping hand is situated
on the subdial at 12 o'clock. This hand makes two complete revolutions in
one hour.
Hour counter: The 12-hour scale with short lines for the 1/2-hour display
with a continuous hand is situated on the subdial at 6 o'clock.
Using the double chronograph
Start: To start the chronograph, press the start/stop button.
Intermediate timing: Actuate the split-seconds-hand button; this will stop
the split-seconds hand, but it will not influence time measurement. You have
now recorded an intermediate time while the standard stopwatch continues
to run. By actuating the split-seconds-hand button once again, you can
cause the split-seconds hand to catch up with the chronograph seconds
hand again, and your chronograph is then ready for the next intermediate
time stop.
Stop: To stop the chronograph, press the start/stop button again. Both
seconds hands stop simultaneously.
Reset: Press the reset button. This will reset all the chronograph hands to
zero. The separately stopped split-seconds hand is not automatically reset,
but must be reset by pressing the split-seconds-hand button again.
Aggregate time recording: You can add stop times together by pressing
the start/stop button again after the first measurement instead of the reset
button.