The period during which hours of daylight are longest in one hemisphere and shortest in the other hemisphere is called the Solstice.
The period during which hours of daylight are longest in one hemisphere and shortest in the other hemisphere is called the Solstice. There are two solstices in a year: the June solstice (around June 21st) in the Northern Hemisphere, where it marks the beginning of summer and has the longest daylight hours, and the December solstice (around December 21st) in the Southern Hemisphere, where it marks the beginning of summer and has the longest daylight hours. During these solstices, the tilt of the Earth's axis is either towards or away from the Sun, causing variations in daylight length across the two hemispheres.
