When are night and day equal?

The state of equality between night and day is called the Equinox phenomenon, which is repeated twice a year, the first of which is on the 20th of March and is called the vernal equinox, and the second occurs on the 22nd of September which is called the Equinox, and the reason for the occurrence of this phenomenon is due to the occurrence of The sun and its perpendicularity above the equator, the vernal equinox is that the duration of the day after that day will begin to increase more than the duration of the night, and vice versa with regard to the autumnal equinox, and as long as the two days of the vernal and autumnal equinoxes witness an equal number of hours between night and day, the moments that precede the vernal equinox and what follow the equinox In the fall, when the day and night are as close as possible to the equinox, it is called an equilux.[1]


The summer solstice means the situation in which the path of the sun is as far as possible, either from the north or south in relation to the Earth’s equator, where the summer solstice occurs in the northern hemisphere on the twentieth or twenty-first of June and the winter solstice either on the twenty-first or twenty-second From the month of December, and the opposite happens in the southern hemisphere, at which the four seasons begin to alternate in reverse. It is worth noting that on the day of the winter solstice, the day is as short as possible and vice versa when the summer solstice occurs.[2]

The reason for the occurrence of night and day

It also appears to our eyes every day that the sun moves in a semi-constant path daily from the east in the morning to the west in the evening, and the reason is due to the rotation of the earth around its axis, which works to change the appearance of the sun on different locations on the surface and its disappearance also, causing the night and day to be according to that earthly movement ,[3] Among the reasons that can also be mentioned in the occurrence of night and day, we mention the following:[4]

  • The occurrence of the sun and the moon in different locations separated by the earth, where the day falls on the side of the globe facing the sun and the night on the side opposite the moon.
  • The Earth revolves around the sun every 365 days for the succession of the four seasons, not for the occurrence of day and night.

the reviewer

  1. ↑ “Why are nights and days different lengths over the year?”, www.bbc.co.uk, 9-22-2017, Retrieved 11-27-2018. Edited.
  2. ↑ “Solstice”, www.britannica.com, Retrieved 11-27-2018. Edited.
  3. ↑ “StarChild Question of the Month for March 2001”, starchild.gsfc.nasa.gov, Retrieved 11-27-2018. Edited.
  4. ↑ “Day and night”, www.education.vic.gov.au, 11-15-2018, Retrieved 11-27-2018. Edited.

When are night and day equal?

Writing – on the date : – Last updated: 2022-05-19 06:57:01