Day and night will get equal time for a brief moment as the equinox arrives. The Earth will experience about the same amount of day and night on Monday when the autumnal equinox arrive. From there, the Northern Hemisphere will plunge into fall as night gets ever longer, and the Southern Hemisphere will head to summer. Solstices are the opposite. They happen in December and March, when the Earth is tilted most strongly toward or away from the sun, so day and night are very different lengths.