Day Length Calculator
Calculate daylight hours, sunrise, sunset, and twilight times for any location. Perfect for photographers, gardeners, and astronomers.
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Calculate Daylight Hours Anywhere
Day length varies dramatically based on your location and the time of year. From the equator's consistent 12-hour days to the polar regions' midnight sun and polar night, understanding daylight patterns helps with photography planning, gardening schedules, and outdoor activities.
What Determines Day Length?
Day length is determined by Earth's axial tilt (23.5°) and its orbit around the Sun. At the equinoxes, day and night are nearly equal worldwide. At the solstices, the difference is most extreme, with polar regions experiencing 24-hour daylight or darkness.
Hour Angle Formula
ω₀ = arccos(-tan(φ) × tan(δ))Why Calculate Day Length?
Photography Planning
Know exact golden hour and blue hour times for stunning outdoor photography.
Gardening & Agriculture
Plan planting schedules based on available daylight for different seasons.
Outdoor Activities
Schedule hiking, fishing, or sports with accurate daylight information.
How to Use This Calculator
Common Applications
Solar Panel Efficiency
Estimate daily solar energy potential based on daylight hours.
Seasonal Planning
Compare day lengths across seasons for activity planning.
Travel Planning
Know daylight conditions at your destination before you travel.
Astronomical Observation
Plan stargazing sessions with accurate darkness times.
Frequently Asked Questions
Civil twilight (sun 0-6° below horizon) has enough light for outdoor activities. Nautical twilight (6-12°) allows horizon visibility at sea. Astronomical twilight (12-18°) ends when the sky is fully dark for observation.