Which of the following statements about headlights is true?

Using headlights half an hour after sunset until half an hour before sunrise is important for ensuring visibility and safety on the road during low-light conditions. This period typically coincides with twilight, when natural light diminishes, and using headlights helps to illuminate the road and make your vehicle more visible to others. It is a standard regulation in many jurisdictions to promote safe driving practices, as well as to comply with traffic laws regarding vehicle lighting.

The other statements lack accuracy. For instance, headlights should not be kept off during the day as many driving conditions can warrant their use, such as drivings in cloudy weather or against the backdrop of glare. Additionally, headlights are necessary not just in rainy conditions; they serve essential functions in various weather conditions and times of the day. Lastly, while older vehicles may have different lighting systems, the use of headlights is not optional based on the vehicle's age but rather is dictated by safety regulations that apply to all vehicles on the road.