About The Auto Light Switch - Casio GB-6900B User's Manual For Watch Functions

About the Auto Light Switch

While the auto light switch is enabled, illumination turns on whenever you position
your wrist as described below in any mode.
Moving the watch to a position that is parallel to the ground and then tilting it
towards you at more than 40 degrees causes illumination to turn on.
Note
•
Auto light is disabled while an alarm is sounding.
Parallel ground More than 40°
E-45