Longitude changes solar time continuously
A full 360° rotation corresponds to about 24 hours, so 15° of longitude corresponds to about one hour of mean solar time. Two places can share a legal clock zone yet have different solar-noon times. Political borders can introduce a clock jump where the Sun’s path changes smoothly.
Noon is a transit, not a fixed clock reading
Local solar noon is when the Sun crosses the local meridian. It differs from civil 12:00 because of longitude within the chosen zone, daylight-saving rules and the equation of time. Record a UTC instant and coordinates when comparing simultaneous observations.
Compare directions at one instant
Hold UTC time fixed in the Sun-position calculator and move longitude. The altitude and azimuth respond to a changed hour angle. Hold longitude fixed and change latitude to see the daily path rise or fall.