Winter solstice

The winter solstice, also called the hibernal solstice, occurs when either of Earth's poles reaches its maximum tilt away from the Sun. This happens twice yearly, once in each hemisphere (Northern and Southern). For that hemisphere, the winter solstice is the day with the shortest period of daylight and longest night of the year, when the Sun is at its lowest daily maximum elevation in the sky. Either pole experiences continuous darkness or twilight around its winter solstice. The opposite event is the summer solstice. The winter solstice occurs during the hemisphere's winter. In the Northern Hemisphere, this is the December solstice (usually 21 or 22 December) and in the Southern Hemisphere, this is the June solstice (usually 20 or 21 of June). Although the winter solstice itself lasts only a moment, the term also refers to the day on which it occurs. The term midwinter is also used synonymously with the winter solstice, although it carries other meanings as well. Traditionally, in many temperate regions, the winter solstice is seen as the middle of winter; although today in some countries and calendars it is seen as the beginning of winter. Other names are the "extreme of winter" (Dongzhi), or the "shortest day". Since prehistory, the winter solstice has been a significant time of year in many cultures and has been marked by festivals and rituals. It marked the symbolic death and rebirth of the Sun; the gradual waning of daylight hours is reversed and begins to grow again. Some ancient monuments such as Newgrange, Stonehenge, and Cahokia Woodhenge are aligned with the sunrise or sunset on the winter solstice. The solstice may have been a special moment of the annual cycle for some cultures even during Neolithic times. Astronomical events were often used to guide activities, such as the mating of animals, the sowing of crops and the monitoring of winter reserves of food. Many cultural mythologies and traditions are derived from this. The winter solstice was immensely important because the people were economically dependent on monitoring the progress of the seasons.