ShanghaiEstimated for your region
In syncmin
Your clock matches the sun right now.
Real solar noon today is at 12:00.
Clock noonSolar noon 12:00
LongitudeYour spot within the time zone-6
Equation of timeEarth's tilt and orbit+6
Daylight savingSummer clock shift0
Total0
Calculated in your browser — your location never leaves it. Privacy
What is solar time?
Solar time is the time told by the Sun's real position in the sky. Its anchor is solar noon — the moment the Sun is due south and at its highest. Your clock instead follows a fixed time-zone offset, so the two rarely line up exactly. The number above is that gap, live for wherever you are, split into longitude, the equation of time, and daylight saving.
Solar time by city
The gap between clock and sun for some of the world's largest cities.
Questions & answers
- Why is my clock ahead of or behind the sun?
- Two steady reasons and one seasonal one. Your city usually sits east or west of the meridian its time zone is centred on, which shifts solar noon earlier or later; the Sun runs a little fast or slow through the year (the equation of time); and daylight-saving time adds an hour on top. Added together, they set how far your clock drifts from the sun.
- What is the equation of time?
- The equation of time is the gap — up to about 16 minutes either way — between clock-even mean solar time and the true Sun, caused by Earth's tilted axis and its elliptical orbit. It is why solar noon wanders across the year even for a city sitting right on its meridian, and why a sundial can read ahead of or behind the clock depending on the date.