Equinox

UTC Date and Time of solstices and equinoxes
year	Equinox Mar		Solstice June		Equinox Sept		Solstice Dec
	day	time	day	time	day	time	day	time
2004	20	06:49	21	00:57	22	16:30	21	12:42
2005	20	12:33	21	06:46	22	22:23	21	18:35
2006	20	18:26	21	12:26	23	04:03	22	00:22
2007	21	00:07	21	18:06	23	09:51	22	06:08
2008	20	05:48	20	23:59	22	15:44	21	12:04
2009	20	11:44	21	05:45	22	21:18	21	17:47
2010	20	17:32	21	11:28	23	03:09	21	23:38
2011	20	23:21	21	17:16	23	09:04	22	05:30
2012	20	05:14	20	23:09	22	14:49	21	11:11
2013	20	11:02	21	05:04	22	20:44	21	17:11
2014	20	16:57	21	10:51	23	02:29	21	23:03
2015	20	22:45	21	16:38	23	08:20	22	04:48
2016	20	04:30	20	22:34	22	14:21	21	10:44
2017	20	10:28	21	04:24	22	20:02	21	16:28

How the Sun lights the Earth on the day of equinox

An equinox is when the sun passes directly over the equator. There are two equinoxes each year. Equinox can also mean either of the two days when this happens. On these days, the nights are equal in length at latitudes L° North and L° South. The word equinox comes from two Latin words meaning "equal" and "night".

Around the day of the equinox, the length of the day is a little over twelve hours and the length of the night is a little under twelve hours. They are not exactly equal because the sun is not a point in the sky and because the sunlight bends as it comes to earth. The exact day and time when this happens depend on how far away from the equator it is being measured. They occur on or around March 21 and September 21. Solstices fall around June 21st and December 21st at odd intervals.

The equinoxes are the beginning of spring, and autumn (or fall in the US).

The time of daylight is quite easy to measure. This was done in many cultures where festivals were celebrated at the equinoxes.

Equinox Media

• 

  Contour plot of the hours of daylight as a function of latitude and day of the year, showing approximately 12 hours of daylight at all latitudes during the equinoxes

• 

  Earth at the September 2022 equinox

• 

  When Saturn is at equinox its rings reflect little sunlight, as seen in this image by Cassini in 2009.

Related pages

• Solstice

References