Calculate sunset time, twilight phases, golden hour, and monthly sunset table for any location. Includes civil, nautical, and astronomical twilight.
Sunset is just the beginning of evening — after the sun dips below the horizon, twilight unfolds in three phases. Civil twilight (sun 0-6° below) provides enough light for outdoor activities. Nautical twilight (6-12°) allows navigation by the horizon. Astronomical twilight (12-18°) is when the sky is dark enough for telescopes. True night begins only when the sun is more than 18° below the horizon.
For photographers, the golden hour — roughly the last hour before sunset — offers warm, directional light ideal for portraits and landscapes. The blue hour follows immediately after, bathing scenes in cool, diffuse blue tones. Planning these windows requires knowing the exact sunset time and twilight progression.
Sunset times vary dramatically with latitude and season. At the equator, sunset shifts by only about 30 minutes year-round. At 50°N, it ranges from 4:00 PM in December to 9:30 PM in June. This calculator provides complete sunset and twilight data for any location on Earth, with a monthly comparison table for seasonal planning.
Photographers plan shoots around golden hour. Astronomers need to know when true darkness begins. Outdoor enthusiasts plan activities around usable daylight. This calculator gives precise twilight timing for any location and season.
This tool is designed for quick, accurate results without manual computation. Whether you are a student working through coursework, a professional verifying a result, or an educator preparing examples, accurate answers are always just a few keystrokes away.
Sunset hour angle: cos(H₀) = (cos(z) − sin(φ)sin(δ))/(cos(φ)cos(δ)), where z = zenith angle (90.833° for geometric sunset, 96° for civil, 102° nautical, 108° astronomical). Sunset = solar noon + H₀/15.
Result: Sunset: 20:31, Civil twilight ends: 21:05
New York on June 21 (summer solstice): sunset at 8:31 PM, with civil twilight lasting until about 9:05 PM. Golden hour starts around 7:30 PM.
Use consistent units throughout your calculation and verify all assumptions before treating the output as final. For professional or academic work, document your input values and any conversion standards used so results can be reproduced. Apply this calculator as part of a broader workflow, especially when the result feeds into a larger model or report.
Most mistakes come from mixed units, rounding too early, or misread labels. Recheck each final value before use. Pay close attention to sign conventions — positive and negative inputs often produce very different results. When working with multiple related calculations, keep intermediate values available so you can trace discrepancies back to their source.
Enter the most precise values available. Use the worked example or presets to confirm the calculator behaves as expected before entering your real data. If a result seems unexpected, compare it against a manual estimate or a known reference case to catch input errors early.
They correspond to how much scattered sunlight remains. Civil: enough for outdoor work. Nautical: horizon visible at sea. Astronomical: sky dark enough for most observations.
No precise definition — roughly the last 60 minutes before sunset (and first 60 after sunrise). The sun is low, warm-toned, and casts long soft shadows.
At low angles, sunlight passes through more atmosphere. Short wavelengths (blue) scatter away, leaving long wavelengths (red, orange). Dust and humidity intensify the colors.
Yes — mountains to the west block the sun earlier. This calculator gives flat-horizon times; actual sunset may be 5-15 minutes earlier in mountainous terrain.
At latitudes above ~60° in summer, the sun never goes more than 18° below the horizon, so it never gets truly dark. St. Petersburg (59.9°N) is famous for this.
Solar declination pushes the sun's path further north (in the Northern Hemisphere), creating a longer arc across the sky and later sunset times. Understanding this concept helps you apply the calculator correctly and interpret the results with confidence.