Publiée le 2007-02-26
Gregorian calendar) is built so as to preserve a fixed date
for the seasons beginning. The date of spring equinox is, in 2006, March 21th, at 0h 7min UTC (1h7min Paris standard time).
n the Northern hemisphere, the spring equinox corresponds to the moment when
apparent longitude of the Sun is equal to 0 degree (the direction of the Sun is
then that of the gamma point, origin of celestial longitudes). Our calendar (the |
Since creation of the Gregorian calendar (1582) the spring equinox is on March 19th, 20th or 21th. At XIXth and XXth centuries it always is on March 20th or 21th. In the past, it was on March 19th in 1652, 1656, 1660,
1664, 1668, 1672, 1676, 1680, 1684, 1685, 1688, 1689, 1692, 1693, 1696, 1697,
1780, 1784, 1788, 1792 and 1796. It will again fall on March 19th in 2044. At the equinox day, if we ignore atmospheric refraction, duration of the night is equal to the duration of the day. It is also the day when
Sun rises full East and lie down full West. The spring equinox in the Northern hemisphere corresponds to the autumn equinox in the Southern hemisphere.