Dates of the equinoxes and solstices

Principles of the solstices

THE SUMMER SOLSTICE

When Saint John’s Day arrives, which corresponds to the start of summer, rituals and bonfires are in order...

The summer solstice is the date of the longest day of the year, and therefore the shortest night, in a hemisphere: Northern hemisphere in June, Southern hemisphere in December.

THE WINTER SOLSTICE

It marks the beginning of winter and is generally associated with a holiday, such as the Roman Saturnalia, Hanukkah in the Jewish religion, Kwanzaa for some African-Americans or Christmas, Sol invictus, Dies natalis solis invicti, celebration of the birth of Mitra, ancient pagan festival assimilated by the Christian religion.

The winter solstice is the shortest day of the year, and therefore the longest night, in a hemisphere: Northern hemisphere in December, Southern hemisphere in June .

The solstices are two times of the year when the sun reaches its southernmost and northernmost positions in relation to the plane of the celestial or terrestrial equator.
On the celestial sphere it then reaches its greatest positive (+23° 26’) or negative (-23° 26’) declination.
Les dates des solstices d’hiver et d’été sont inversées pour les hémisphères Nord et Sud.

Principles of the equinoxes

The quinox corresponds to time of year when the sun is at the zenith at the terrestrial equator, the earth is then at right angle (taking the poles) with the rays of the sun.
Day and night then have the same duration.

Here is a short video found on Youtube

Precise dates and times of the solstices and equinoxes

The times below are in Eastern Standard Time (EST = UT - 5 hours)
Add an hour when Eastern Daylight Time is in effect.

To find the years after those provided in this table, consult thee promenade imcce serveurfrom the Institute of Celestial Mechanics and Calculation of the Ephemerides (IMCCE) of the Paris Observatory.