NovelNumbers

Golden hour: the period when the sun's elevation is between −4° and +6° above the horizon — the standard photography convention. Morning golden hour begins slightly before sunrise and ends once the sun climbs past 6°; evening golden hour begins when the sun drops below 6° and ends slightly after sunset. All times account for daylight saving transitions automatically for the selected time zone.

Civil twilight: the period when the sun is between 0° and −6° below the horizon. There's usually enough natural light to see clearly outdoors without artificial lighting, and on clear days the horizon is still visible.

Nautical twilight: the period when the sun is between −6° and −12° below the horizon. The horizon is no longer clearly visible, but general shapes and the brightest stars and planets become visible — historically used by sailors for celestial navigation.

Astronomical twilight: the period when the sun is between −12° and −18° below the horizon. The sky is essentially dark to the naked eye, though residual sunlight can still faintly affect the faintest astronomical observations. Once the sun drops below −18°, it's considered full night.