Q&A Q: Why is the light not on after installing the battery? A: 1. Switch is turned to "I" or "II" 2. Use the new batteries, and the "+" and "-" terminals aligned properly. 3. In a dark environment Q: How long can the led light be on? A: Using alkaline new batteries, the light can be continuously lit for about 6 months. Q: Why does the light not turn on at night? A: After the light is on for 5 hours, it will automatically turn off to save battery OCEST Outdoor Clock 12-inch Outdoor Clock Add To Basket 13-inch Outdoor Clock Add To Basket 13-inch Outdoor Clock Buying Options 15-inch Outdoor Clock Add To Basket 16-inch Outdoor Clock Add To Basket 16-inch Outdoor Clock Buying Options Customer Reviews 4.3 out of 5 stars 75 4.4 out of 5 stars 378 4.0 out of 5 stars 54 4.6 out of 5 stars 42 4.4 out of 5 stars 178 4.