September 22-23 & March 21-22. They mark the beginnings of autumn and spring respectively, in the northern hemisphere. They mark the beginnings of spring and autumn, respectively, in the Southern Hemisphere.
The Spring equinox and the Autumnal equinox occur when the length of daytime and the length of nighttime are exactly equal to each other.
Equinoxes
Auroras occur most frequently during the months of March and September due to increased solar activity and Earth's alignment with the sun during the equinoxes. However, they can also be observed in northern and southern latitudes during the winter months.
Auroral displays are most often seen in the months of March, April, September, and October. These months correspond to the equinoxes when solar activity tends to produce more intense geomagnetic storms.
The year has two equinoxes, which are the days on which the night and day are of equal length. They happen when the apparent position of the Sun (on the ecliptic) crosses the Earth's equator.The equinoxes are usually March 21 and September 22, and on those days the Sun has a declination of zero and is overhead at the equator.
On the equinoxes, the sun's direct rays fall on the equator. This causes day and night to be of equal length all over the world.
There are two equinoxes per year, separated by about 6 months. There will never be two equinoxes in one month.
They occur around 20 March and 23 September.
6 months
An unveiling can take place anywhere from a few months to 11 months after the burial.
9 months after valentines day
till july
Equinoxes
"Heroes of Olympus" takes place about six months after the events of "The Last Olympian."
June 1950 to July 1953.
April 1861 - April 1865
Because the Earth is going around the sun every 365-366 days. The equinoxes create the seasons such as spring, summer, fall, and winter. Each equinox is a place on the circle of the Earths path.
August and July are the two months in the Gregorian calendar that do not have a solstice or an equinox.