Sunrise & Sunset Calculator
Solar position algorithm — equinox-day-of-year + latitude → sunrise + sunset + solar noon. Within ±2 min of NOAA Sun Calculator for ±60° lat.
Result
- Date__TODAY__
- Latitude40.7128°
- Longitude-74.0060°
- Day of year143
- Solar declination20.43°
- Equation of time3.60 min
- Solar noon (UTC)16:52:25
- Sunrise (UTC)09:32:41
- Sunset (UTC)00:12:09
- Local TZ offset-5 hr
- Sunrise (local)04:32:41
- Solar noon (local)11:52:25
- Sunset (local)19:12:09
- Day length14 hr 39 min
Step-by-step
- Day of year N = 143.
- Fractional year γ = 2π/365 · (143−1) = 2.4444 rad.
- Equation of time = 3.60 min; declination δ = 20.43°.
- Hour angle H = acos((cos 90.833° − sin φ · sin δ) / (cos φ · cos δ)).
- Solar noon = 12:00 UTC − 4·lon − EoT; sunrise/set = noon ∓ H · 4 minutes.
How to use this calculator
- Enter your latitude (north positive) and longitude (east positive). Most map apps export decimal-degree coordinates directly.
- Pick the date — defaults to today.
- Enter your time zone offset from UTC — for US EST use -5, US PDT (with DST) use -7, UK BST use +1, India use +5.5.
- Read sunrise / sunset / solar noon in both UTC and local time.
About this calculator
A simplified version of the NOAA solar-position algorithm — accurate to ±2 minutes between latitudes −60° and +60°, less accurate near the poles where refraction and rapid declination shifts dominate. The algorithm: (1) compute the day-of-year N; (2) compute solar declination and equation-of-time from N via Fourier series approximations; (3) compute the hour angle at sunrise/sunset using the 90.833° zenith angle (= 90° + 0.833° atmospheric refraction at the horizon); (4) convert hour angle to clock time. The 90.833° zenith accounts for the sun's ~0.27° apparent radius plus ~0.567° standard atmospheric refraction. At polar latitudes, the sun may not rise or set on a given date (polar night/day) — those cases are flagged. For higher precision (±10 sec), use the full NOAA SPA (Solar Position Algorithm, Reda & Andreas 2004) or the U.S. Naval Observatory Astronomical Almanac formulas.