How many days until Fall Equinox?

About Fall Equinox

The fall equinox, also called the autumnal equinox in the Northern Hemisphere, marks the moment the sun crosses directly over Earth's equator, resulting in day and night of approximately equal length across most of the planet and traditionally signaling the astronomical start of autumn. In the Northern Hemisphere this occurs in September, while the Southern Hemisphere experiences its fall equinox in March, since the same astronomical alignment produces opposite seasonal transitions depending on hemisphere. The date shifts slightly from year to year, generally falling on September 22 or September 23, because the exact moment is defined by the precise instant of the sun's alignment with the equator, calculated in Coordinated Universal Time, which does not align perfectly with the calendar year and can shift the specific local date depending on time zone. As with the spring equinox, the term suggesting perfectly equal day and night is only approximately accurate; atmospheric refraction and the sun's disc-shaped rather than point-like appearance mean daylight is actually somewhat longer than night on the equinox itself in most locations, with the day of truly equal daylight and darkness typically falling a few days after the equinox in many regions. The day has held symbolic significance across many cultures throughout history, often associated with harvest, balance, and the transition into shorter days, influencing numerous autumn festivals and traditions worldwide. A common misconception is assuming day and night are exactly equal on the equinox itself, when in practice the truly equal-length day usually occurs a few days later.

Dates on this page are checked against public calendar sources. Spot something wrong? Let us know.