Compute sunrise, sunset, solar noon, day length and the solar elevation angle for any location and date using standard NOAA solar astronomy (solar declination, equation of time, hour angle) — runs entirely in your browser.
e.g. +8 for Beijing, −5 for New York
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Sunrise
When the sun's upper limb first appears above the horizon (zenith 90.833°)
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Sunset
When the sun's upper limb last disappears below the horizon (zenith 90.833°)
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Solar noon
The instant the sun crosses the local meridian and reaches its highest point
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Day length
Time between sunrise and sunset
Solar geometry details
Solar elevation (noon max)
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Sun declination (δ)
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Equation of time
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Hour angle of sunrise
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NOAA approximation: zenith 90.833° accounts for atmospheric refraction (~34′) and the sun's semi-diameter (~16′). Solar elevation at noon = 90° − |latitude − declination|. Timezone is a fixed UTC offset — adjust manually when daylight saving applies.
Enter latitude (+ for North), longitude (+ for East), pick a date and the UTC timezone offset, then click Calculate. The calculator follows NOAA Solar Calculations: it finds the Julian Century, the sun's geometric mean longitude and anomaly, the equation of center, declination δ and the equation of time EoT, then the sunrise hour angle H = acos(cos(90.833°)/(cosφ·cosδ) − tanφ·tanδ). Solar noon = 720 − 4·longitude − EoT + tz·60 (minutes). Sunrise = noon − 4H, sunset = noon + 4H. Noon elevation = 90° − |φ − δ|. Use a city preset or the geolocation button to fill coordinates automatically.