What this tool does
The Sunrise & Sunset Calculator computes the exact times for sunrise, sunset, solar noon, and twilight for any location on Earth and any date. It also calculates golden hour windows, beloved by photographers, and the three twilight phases used by astronomers, navigators, and pilots.
Enter a city name or geographic coordinates, choose a date, and instantly see a full picture of the sun's daily journey for that location.
How sunrise and sunset are calculated
Sunrise and sunset times are calculated using the solar position equations developed by the National Oceanic and Atmospheric Administration (NOAA). The core calculation involves:
**Solar declination** means how far the sun is north or south of the equator on a given date. This varies from +23.45 degrees at the summer solstice to -23.45 degrees at the winter solstice.
**Equation of time** is a correction factor that accounts for Earth's elliptical orbit and axial tilt, which cause the real sun to run slightly ahead or behind a hypothetical mean sun.
**Hour angle** is the angular distance between the sun's current position and solar noon, measured in degrees (15 degrees per hour).
The combined formula: cos(hour_angle) = (cos(zenith) - sin(lat) x sin(decl)) / (cos(lat) x cos(decl))
For sunrise, zenith = 90.833 degrees (accounting for atmospheric refraction and the sun's apparent radius).
Twilight phases explained
Twilight occurs when the sun is below the horizon but still illuminates the sky. There are three defined phases based on how far below the horizon the sun sits:
**Civil twilight** (sun 0 to 6 degrees below horizon): Enough natural light for outdoor activities without artificial lighting. The horizon is clearly visible.
**Nautical twilight** (sun 6 to 12 degrees below horizon): Historically used by sailors. The horizon is still visible, and the brightest stars can be seen for celestial navigation.
**Astronomical twilight** (sun 12 to 18 degrees below horizon): The sky is dark enough for most astronomical observations. True astronomical darkness begins when the sun is more than 18 degrees below the horizon.
Golden hour for photography
Golden hour refers to the period shortly after sunrise and shortly before sunset when the sun is near the horizon. During this time:
- Sunlight travels through more atmosphere, scattering blue wavelengths - The remaining warm reds, oranges, and yellows create a soft, golden glow - Shadows are long and dramatic, adding depth to landscapes - Harsh midday contrast is eliminated, ideal for portraits and landscapes
This calculator shows the golden hour window as the period when the sun is between 0 and 6 degrees above the horizon, roughly the first and last hour of daylight.
Solar noon
Solar noon is the moment when the sun reaches its highest point in the sky. At solar noon, the sun is due south (in the northern hemisphere) or due north (in the southern hemisphere). It is exactly halfway between sunrise and sunset.
Solar noon is rarely 12:00 PM on the clock. The difference between solar noon and clock noon can be 30 minutes or more, depending on your position within your time zone and the equation of time correction.
Note: All times in this calculator are in local solar time based on longitude. To convert to your clock time, you would need to apply timezone offset and daylight saving adjustments.
Polar regions and extreme latitudes
At latitudes above the Arctic Circle (approximately 66.5 degrees N) or below the Antarctic Circle (approximately 66.5 degrees S), the sun may not rise or set at all on certain dates:
**Polar day (midnight sun)**: The sun stays above the horizon for 24 hours. Occurs in summer months at extreme latitudes.
**Polar night**: The sun stays below the horizon for 24 hours. Occurs in winter months at extreme latitudes.
The calculator indicates "No Sunrise" or "No Sunset" when these conditions occur for the selected location and date.
How to use
1. Choose between city name or coordinate entry using the toggle 2. Type a city name (e.g., London, Tokyo, New York) or enter latitude and longitude 3. Alternatively, click "Use My Current Location" to auto-fill coordinates 4. Select the date you want to calculate 5. Click "Calculate Sun Times" to see results 6. View sunrise, sunset, solar noon, day length, golden hour, and twilight times
FAQs
Q: Why doesn't the time match my weather app's sunrise time? A: This calculator shows local solar time based on longitude, not your clock time. Your weather app accounts for your timezone and daylight saving time. The difference is typically 0 to 60 minutes depending on your location.
Q: What is the equation of time? A: It is a correction for the fact that Earth moves slightly faster when closer to the sun (January) and slower when farther away (July). This makes the real sun appear to run up to 16 minutes ahead or behind a mean sun, affecting solar noon and sunrise/sunset times.
Q: Why is the golden hour not exactly one hour? A: "Golden hour" is a loose term. The actual duration depends on your latitude and the season. Near the equator it can be as short as 20 minutes. Near the poles, the sun moves so slowly that golden hour can last for hours.
Q: How accurate are these calculations? A: The solar position algorithm used is accurate to within 1 to 2 minutes for most dates and latitudes. For very high latitudes (above 70 degrees), accuracy may decrease slightly. For professional or scientific use, consult NOAA's solar calculator directly.
Q: What is astronomical darkness? A: True darkness occurs when the sun is more than 18 degrees below the horizon, after astronomical twilight ends and before it begins. This is when you can see the faintest stars and conduct serious astronomical observations.
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