Calculate sunrise, sunset, daylight hours, and twilight durations for any latitude and day of the year using solar position equations.
The amount of daylight at any location on Earth depends on two key factors: latitude and the time of year. Near the equinoxes, everywhere on Earth receives approximately 12 hours of daylight. But as the seasons progress, higher latitudes experience dramatic changes—from nearly 24 hours of light in summer to almost total darkness in winter polar regions.
This daylight calculator uses precise solar position algorithms to compute sunrise, sunset, daylight duration, and twilight periods for any latitude and any day of the year. It accounts for atmospheric refraction, observer elevation, and the equation of time to give you accurate results that match published almanac data.
Beyond simple sunrise and sunset times, the calculator breaks down the full day into its components: direct sunlight, civil twilight (when outdoor activities are still possible), nautical twilight, astronomical twilight, and true night. This complete picture is invaluable for photography planning, outdoor activities, astronomical observation, and understanding our planet's orbital mechanics.
Whether you're planning photography golden hours, agricultural activities, outdoor events, or just curious about seasonal light patterns, this calculator provides precise daylight information for any location and date without needing specialized astronomy software.
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.
Solar declination: δ = 0.006918 − 0.399912cos(γ) + 0.070257sin(γ) − ... Hour angle: cos(H) = [cos(90°) − sin(φ)sin(δ)] / [cos(φ)cos(δ)] Daylight hours = 2H / 15 Equation of Time: EoT = 229.18 × [0.000075 + 0.001868cos(γ) − 0.032077sin(γ) − ...] Where γ = (2π/365)(day − 1) and φ = latitude.
Result: 15h 37m daylight, sunrise 04:32, sunset 20:09
At 45°N latitude on the summer solstice (day 172), there are about 15 hours and 37 minutes of daylight, with sunrise around 4:32 AM and sunset around 8:09 PM solar time.
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.
This calculator uses geometric sunrise/sunset with standard atmospheric refraction. Local terrain, actual atmospheric conditions, and precise longitude within a timezone can cause differences of 1–3 minutes.
Civil twilight is the period when the sun is between 0° and 6° below the horizon. There is enough light to see objects clearly outdoors without artificial light. It lasts about 30 minutes at mid-latitudes.
When the solar declination exceeds the co-latitude (90° − latitude), the sun never dips below the horizon. This occurs inside the Arctic/Antarctic circles during their respective summers.
Higher elevation allows you to see the sun earlier because your geometric horizon is lower. Each 100m of elevation gains roughly 1 minute of extra daylight.
The equation of time accounts for Earth's elliptical orbit and axial tilt, which cause solar noon to drift by up to ±16 minutes from mean solar time throughout the year. Understanding this concept helps you apply the calculator correctly and interpret the results with confidence.
No, results are in solar time adjusted by your UTC offset. Add 1 hour during daylight saving time periods.