Work out solar noon instantly with clear inputs, formula shown and shareable results.
Solar noon is when the Sun crosses the local meridian, and it drifts from clock noon for two reasons: longitude offset within the time zone at four minutes per degree, and the equation of time, which swings plus or minus 15 minutes over the year because Earth's orbit is elliptical and its axis tilted.
Solar noon
minutes = 720 - 4 x longitude - equation of time + timezone x 60
Equation of time
EoT = 9.87 sin(2B) - 7.53 cos(B) - 1.5 sin(B), B = 360(n - 81)/364
Time zones are wide, so most places sit degrees away from their standard meridian, and the equation of time adds up to a further quarter hour either way.
About +16 minutes in early November and -14 minutes in mid February, which is why sunset times shift asymmetrically around the solstice.