Calculate the exact time of solar noon, sunrise, sunset, and day length for any location and date. Includes equation of time, solar declination, and twilight times.
The Solar Noon Calculator determines the exact moment when the sun reaches its highest point in the sky for any location and date. Solar noon rarely coincides with 12:00 PM clock time — it varies based on your longitude within your time zone and the equation of time, which fluctuates by up to ±16 minutes throughout the year.
The calculator also computes sunrise, sunset, civil/nautical/astronomical twilight, day length, and the solar declination angle. Enter your latitude, longitude, and time zone offset to get precise times for any date, or use the built-in city presets.
Photographers use solar noon to plan golden hour shoots. Sundial enthusiasts need the equation of time correction. Solar panel installers optimize tilt angles based on declination. This calculator serves all these needs with astronomical accuracy. Check the example with realistic values before reporting. Use the steps shown to verify rounding and units. Cross-check this output using a known reference case.
Find exact solar noon, sunrise, and sunset times for any location. Essential for photography, solar energy planning, sundial correction, and understanding seasonal daylight patterns. Keep these notes focused on your operational context. Tie the context to the calculator’s intended domain. Use this clarification to avoid ambiguous interpretation. Align this note with review checkpoints.
Solar Noon = 12:00 - Longitude/15 + Timezone - EoT/60. Equation of Time (EoT) uses the Spencer formula. Solar Declination = 23.45° × sin(360/365 × (284 + day_of_year)). Sunrise/Sunset Hour Angle = acos(-tan(lat) × tan(declination)).
Result: Solar noon: 12:58 PM, Sunrise: 5:25 AM, Sunset: 8:31 PM
New York City on the summer solstice. Solar noon is 12:58 PM (not exactly noon) because NYC is west of its timezone center. Day length: 15h 6m — the longest day of the year.
The equation of time has two components: (1) the eccentricity of Earth's orbit causes the sun to appear to speed up and slow down relative to a perfect clock, and (2) the obliquity (tilt) of the ecliptic causes the sun's apparent motion along the celestial equator to be non-uniform even if Earth's orbit were perfectly circular.
These two effects combine to create the familiar figure-8 analemma. The maximum deviation is about +14 minutes in early February (sundial runs fast) and -16 minutes in early November (sundial runs slow).
At the equator, day length is nearly constant at 12 hours year-round. With increasing latitude, seasonal variation grows dramatically. At 45°N, the longest day is about 15.5 hours and the shortest about 8.5 hours. At the Arctic Circle (66.5°N), the sun doesn't set for at least one day at the summer solstice and doesn't rise for at least one day at the winter solstice.
Solar panel installers use solar noon to determine the optimal azimuth (south-facing in the Northern Hemisphere). Solar declination determines the optimal tilt angle. Farmers and gardeners use day length to plan planting. Astronomers need astronomical twilight times to plan observations. And sundial enthusiasts need the equation of time to convert sundial readings to clock time.
Two reasons: (1) Your longitude within the time zone — time zones span 15° but use a single clock time, so locations east of the zone center see solar noon earlier than noon. (2) The equation of time — Earth's orbital eccentricity and axial tilt cause solar time to deviate from clock time by up to ±16 minutes.
The difference between apparent solar time (sundial time) and mean solar time (clock time). It's caused by Earth's elliptical orbit (faster near perihelion) and the 23.45° axial tilt. The combined effect creates a figure-eight pattern called the analemma.
The angle between the sun's rays and Earth's equatorial plane. It ranges from +23.45° (summer solstice in Northern Hemisphere) to -23.45° (winter solstice). At 0° (equinoxes), day and night are approximately equal everywhere.
The period shortly after sunrise and before sunset when sunlight is warm, soft, and directional. Typically the first/last hour of sunlight. This calculator shows sunrise and sunset so you can plan golden hour shoots.
Within 1-2 minutes for sunrise/sunset and solar noon. Professional astronomical calculators account for atmospheric refraction, observer elevation, and precise orbital elements, which can shift times by ±1 minute.
Civil twilight: sun 0-6° below horizon (can read outdoors). Nautical twilight: sun 6-12° below (horizon still visible at sea). Astronomical twilight: sun 12-18° below (sky appears dark for astronomy).