☀️ Solar Ephemeris & Day Length
Sunrise, Sunset & Solar Noon Calculator
Calculate solar transit, sunrise, sunset, day length, and golden hour intervals for any coordinates.
World Cities:
London (51.5° N)
New York (40.7° N)
Tokyo (35.7° N)
Paris (48.9° N)
Sydney (33.9° S)
Cairo (30.0° N)
🌅 Sunrise
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☀️ Solar Noon
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🌇 Sunset
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⏳ Daylight Length
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Dawn, Dusk & Twilight Intervals:
| Twilight Phase | Sun Angle | Dawn (Morning) | Dusk (Evening) |
|---|---|---|---|
| Civil Twilight | 0° to 6° below horizon | - | - |
| Nautical Twilight | 6° to 12° below horizon | - | - |
| Astronomical Twilight | 12° to 18° below horizon | - | - |
| Golden Hour | 6° above to 4° below | - | - |
Solar Geometry & NOAA Calculation Formulas
The calculations in this tool implement standard astronomical solar ephemeris algorithms adapted from the NOAA (National Oceanic and Atmospheric Administration) Solar Calculator:
- Solar Declination ($\delta$): The angle between the rays of the Sun and the plane of the Earth's equator.
- Hour Angle ($\omega$): The angular distance of the Sun west of the local meridian: $\cos(\omega_0) = \frac{\sin(\alpha) - \sin(\phi)\sin(\delta)}{\cos(\phi)\cos(\delta)}$ where $\alpha = -0.833^\circ$ for standard sunrise/sunset (accounting for atmospheric refraction and solar disc diameter).
- Solar Noon ($T_{\text{noon}}$): The exact moment when the Sun crosses the celestial meridian and reaches its highest elevation in the sky for the day.