December is one of two months to have a solstice (the other is June, its seasonal equivalent in both hemispheres), and in this month the Tropic of Capricorn in the Southern Hemisphere is turned towards the Sun, meaning that December 21 or December 22 is the Northern Winter Solstice and the Southern Summer Solstice. This means that this date would have the least daylight of any day in the Northern Hemisphere, and the most in the Southern Hemisphere. There are 24 hours of darkness at the North Pole and 24 hours of daylight at the South Pole.