How do you set auto light on G Shock ga-110c?

To set the auto light feature on a G-Shock GA-110C, first ensure the watch is in Timekeeping Mode. Then, press and hold the "Adjust" button until the watch beeps and the settings screen appears. Use the "Mode" button to cycle to the auto light setting, and then use the "Search" button to toggle it on or off. After setting it, press the "Adjust" button again to exit the settings.