Yes it does. During the bright summer months when the sun is out constantly, you can expect to see fast and efficient charging times for your watch. It is during winter and late fall that you need to be careful about how effectively your watch charges. Factors such as less light, shorter days, and winter clothes can all contribute to your watch failing to charge perfectly. During these months, it is a good idea to make changes to your behavior to ensure that you get the most out of the light and keep your watch fully charged for when you need it.