When do all locations on Earth experience 12 hours of daylight and 12 hours of darkness?

All locations on Earth experience approximately 12 hours of daylight and 12 hours of darkness during both the Spring Equinox and the Autumnal Equinox. This phenomenon occurs because, during these equinoxes, the angle of the Earth's tilt is such that the sun is positioned directly above the equator. As a result, sunlight is distributed evenly across both hemispheres, leading to equal day and night lengths regardless of the location's latitude.

Specifically, the equinoxes occur around March 21 for the Spring Equinox and around September 23 for the Autumnal Equinox. During these times, the sun rises in the east and sets in the west, creating consistent day lengths globally.

In contrast, during the Summer Solstice, regions above the Arctic Circle experience continuous daylight, while areas in the Antarctic Circle may have 24 hours of darkness, and vice versa during the Winter Solstice. Thus, these solstices do not result in equal day and night durations.