Sunrise and Sunset Time Calculator
Calculate sunrise and sunset times for any date and location.
Find day length, golden hour, and civil twilight times.
Sunrise and sunset times are critical for navigation, aviation, sailing, photography, and outdoor planning. Times vary by latitude, longitude, and date.
The key factors:
- Latitude: The closer to the poles, the more extreme the seasonal variation. At the equator, day length is nearly constant at 12 hours year-round. At 60°N in summer, the sun may set well past 22:00.
- Longitude: Determines your position within a time zone. Two cities in the same time zone but far apart in longitude can have sunrise times that differ by 30+ minutes.
- Date: The Earth’s axial tilt (23.5°) causes the seasons. At the summer solstice (around June 21 in the northern hemisphere), the sun rises earliest and sets latest.
Civil twilight: Begins when the sun is 6° below the horizon. There is enough light to see clearly, but the sun is not yet visible. Many aviation regulations use “civil twilight” as the boundary for VFR flight and navigation lights.
Nautical twilight: Sun 12° below horizon. Horizon is visible but sky is dark — traditional celestial navigation is possible.
Golden hour: The first and last hour of sunlight. Low angle, warm tones. Highly valued by photographers.
Day length formula (approximate): D = 24 − (24/pi) × arccos((sin(p) + sin(lat) × sin(dec)) / (cos(lat) × cos(dec)))
Where p = -0.0145 radians (sun just below horizon), lat is latitude, dec is solar declination.
For precise navigation, always verify with official almanac data (USNO, UKHO).