Special conditions1 of 2
Washington law requires headlights to be on from:
The answer
Answer: B. The legal requirement runs from half an hour after sunset to half an hour before sunrise. The guide suggests an easier habit: use headlights all the time, or at least whenever it is dark, rainy, snowy, foggy or smoky. Headlights help you see, and they also help others see you.
Source: Washington Driver Guide — 2.5 Vehicle maintenance (headlights)