September 23rd, the Autumn Equinox. To Celts - this is the Second Harvest, when the ripe Acorns fall from the wild Irish Oaks and we plant them in fertile soil. This wonderful time is the time when day and night are equal in length. Equinox meaning "equal night".
In Ireland there is an ancient Irish equinox temple at Knowth, near Newgrange (BrÃº na Boinne). Knowth has a 100-foot long passage that only is light by the Sun on the morning of the Spring and Autumn Equinox.The Autumn Equinox is sometimes referred to as the Fall Equinox – Fall means ‘leaf fall’ so together the Fall Equinox means “Leaf Fall Equal Night and Day”.
To the Celtic Druids this is the Second Harvest. A time when the ripe acorns fall from the wild Irish Oaks and they are plant in fertile soi. The “Harvest Moon” was so-called in the past because night harvests were possible by the light on the Full Moon nearest to the autumn or fall equinox. In Ireland the autumn equinox was celebrated long before the arrival of the Celtic tribes.