Sunset, also known as sundown, is the daily disappearance of the Sun below the horizon due to Earth's rotation. As viewed from everywhere on Earth, the equinox Sun sets due west at the moment of both the Spring and Autumn equinox. As viewed from the Northern Hemisphere, the sun sets to the northwest in the Northern hemisphere's spring and summer, and to the southwest in the autumn and winter; these seasons are reversed for the Southern Hemisphere.
