Auto light feature will not work if the battery level falls below Medium (marked as M on the face of the watch).</br>Turn on or off the auto light function by holding down the light button and turn wrist at a 40 degree angle towards the user in a dark environment</br>Casual solar-powered watch with multiple functions including multi-band atomic timekeeping?? shock resistance?? EL backlight?? world time (29 time zones?? 48 cities)?? city code display?? five daily alarms?? 1/100-second stopwatch?? countdown timer?? full auto-calendar?? battery indicator?? and power-saving function</br>Approximate battery life: 10 months o