Civil Twilight
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Sun crosses 6° below horizon
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Sun crosses 6° below horizon
Current Local Time
—This civil twilight calculator shows the exact civil dawn and civil dusk times (sun 0°–6° below horizon) for any location.
What Is Civil Twilight?
Civil twilight occurs when the sun is between 0 and 6 degrees below the horizon — a bright enough period that the sky provides sufficient natural light for most outdoor activities without artificial illumination. During civil dawn (before sunrise) and civil dusk (after sunset), the horizon remains clearly visible, colors are soft and muted, and the sky transitions through pale pink, orange, and lavender tones.
Civil twilight is the most practically useful twilight phase — it marks the boundary where you can still see clearly enough to walk, drive, and work outdoors without lights. Many aviation regulations and construction safety rules define civil twilight as the legal cutoff for when headlights and reflective gear become required. For photographers, it provides the soft, even light that flatters portraits and landscapes without the harsh contrast of direct sun.
How Our Civil Twilight Calculator Works
Our civil twilight calculator determines the exact times when the sun reaches 6 degrees of depression below the horizon at your location, marking the start and end of the civil twilight window. It uses the SunCalc library with standard atmospheric refraction of 0.833° applied, and runs entirely in your browser.
The tool applies the standard solar algorithm with refraction corrections and elevation adjustments to provide both morning civil twilight and evening civil twilight durations accurate to the nearest minute. No data is sent to any server — the entire computation is local and instant.
FAQ — Civil Twilight
What time does civil twilight start in the morning?
Civil dawn begins when the sun reaches 6° below the horizon, typically 20-35 minutes before sunrise depending on your latitude and season. Use the calculator above for exact times. I've found that the most productive morning outdoor activity window is during civil twilight — there's enough light to see clearly, but the air is still cool and calm.
Can I see stars during civil twilight?
Only the brightest stars and planets are visible during civil twilight. The sky is still too bright for most stars. Venus, Jupiter, and Sirius can typically be spotted. For serious stargazing, you need to wait until nautical twilight (sun below 6°) or better yet astronomical twilight (sun below 18°) when the sky is truly dark.
How long does civil twilight last?
Civil twilight typically lasts 20-35 minutes at most latitudes, but it can be much longer near the poles where the sun skims the horizon at a shallow angle. Near the equator, it's shorter — sometimes just 20 minutes — because the sun rises and sets steeply. The calculator gives you exact durations for your location.
What's the legal significance of civil twilight?
In many jurisdictions, civil twilight defines when headlights become legally required on vehicles, when construction workers must wear reflective gear, and when certain outdoor events need permits. Aviation authorities also use civil twilight to determine when visual flight rules apply. The exact legal definition may vary by country or state, but it's generally tied to the sun being 6° below the horizon.
Is civil twilight the same as golden hour?
No — golden hour occurs when the sun is 0-6° above the horizon (direct sunlight), while civil twilight occurs when it's 0-6° below (indirect light). Golden hour produces warm, directional light with long shadows. Civil twilight produces cool, even, shadowless light. They're adjacent periods — civil twilight leads directly into golden hour at sunrise, and golden hour leads into civil twilight at sunset.