How to use it
- Enter the From year and the To year, from 1900 to 2100.
- Type the Time zone you want, for example Europe/Istanbul or America/New_York.
- Read the Equinoxes and solstices table. The UTC column is the same everywhere, and Your time zone shows the same moment on your clock.
How the moments are found
An equinox is the moment the Sun crosses the celestial equator, so day and night are close to equal everywhere. A solstice is the moment the Sun is farthest north or south of the equator, which gives the longest or the shortest day of the year in each hemisphere.
The page uses the Seasons function of astronomy-engine, an open-source astronomy library. It finds the instant when the Sun's apparent ecliptic longitude, seen from the centre of the Earth, reaches each of four values.
March equinox: Sun's longitude = 0°
June solstice: Sun's longitude = 90°
September equinox: Sun's longitude = 180°
December solstice: Sun's longitude = 270°Time zones and daylight saving time
The UTC column is Universal Time, the same for every reader. The last column converts that moment with the rules of the zone you typed for that exact date, including daylight saving time where the zone uses it.
Because of the offset, the local date can be one day earlier or later than the UTC date. The September equinox of 2026 falls at 00:06 UTC on 23 September, which is still 22 September in New York.
What this page does not cover
- The sunrise, the sunset and the length of the day at a place. Those depend on the location as well as the moment.
- The moments of other events of the Sun or the Moon, such as the perihelion or the lunar phases. For the Moon, see the moon phase tool.
Worked example: 2026 in New York
For 2026, with the time zone America/New_York, the four moments are as the table shows. New York was on daylight time from 8 March to 1 November 2026, so its clock was four hours behind UTC in that period and five hours behind in December.
| Event | UTC | New York time |
|---|---|---|
| Spring equinox | Mar 20, 2026, 14:46 UTC | Mar 20, 2026, 10:46 EDT |
| Summer solstice | Jun 21, 2026, 08:25 UTC | Jun 21, 2026, 04:25 EDT |
| Autumn equinox | Sep 23, 2026, 00:06 UTC | Sep 22, 2026, 20:06 EDT |
| Winter solstice | Dec 21, 2026, 20:50 UTC | Dec 21, 2026, 15:50 EST |
Frequently asked questions
What is the difference between an equinox and a solstice?
An equinox is the moment the Sun crosses the celestial equator, in March and in September. A solstice is the moment the Sun is farthest from the equator, in June and in December, which gives the longest or shortest day in each hemisphere.
Why do the dates change from one year to the next?
The year is not a whole number of days, so each season starts a few hours later or earlier than in the year before. The date moves by a day now and then, and leap years reset the pattern.
Should I use UTC or my local time?
UTC is the same everywhere and is the time astronomers publish. Use the local column for a plan in that place, because it shows the same moment on the clock of the zone you typed.
How accurate are the times on this page?
The times agree with the US Naval Observatory's published table to within two minutes for the years checked, 1900, 1950, 2000, 2026, 2030 and 2100. The table is given in whole minutes, so a difference of one minute is normal.
Are the seasons in the Southern Hemisphere on the same dates?
The moments are the same, but the seasons are reversed. The March equinox starts autumn in the Southern Hemisphere, and the June solstice starts winter there.
Sources
- US Naval Observatory, Earth's seasons: the table used to check the times on this page
- astronomy-engine, the open-source MIT-licensed library that computes the Seasons function
Figures and text last checked on Wednesday, November 11, 2026.