In the United Kingdom, the "legal" definition of night varies significantly depending on which law is being applied. For road traffic lighting, "night" (or the "hours of darkness") is defined as the period between half an hour after sunset and half an hour before sunrise. This is when vehicles are legally required to use their headlights. However, for employment law and the "Night Worker" regulations, "night time" is defined as a period of at least seven hours which must include the time between midnight and 5:00 AM. For planning and noise nuisance purposes, "night" is often considered to be between 11:00 PM and 7:00 AM. Finally, in the context of aviation and pilot licensing, "night" is defined by the Civil Aviation Authority (CAA) as the time from 30 minutes after sunset until 30 minutes before sunrise (similar to road law). Understanding these varied definitions is crucial for your database, as "night" isn't just a celestial event—it's a regulatory framework that determines everything from your pay rate at a hospital to whether your car's lights must be on during a foggy evening in London.