It is the precise moment when the Sun appears the farthest south in the sky. It is the day with the fewest hours of possible sunlight and the longest hours of darkness.
According to the US Naval Observatory, in 2024 this time will be 3:19 AM on Saturday, December 21.
Winter Solstice is a celebration of light, but it's DARK during the Winter why is it a celebration of light? Why do humans choose to celebrate the Sun during this dark and dreary time of year? So much darkness makes you want to stay inside and hibernate, to pass the winter conserving as much energy as possible. Yet around the world, it’s a day that crowds of people go outside to celebrate the “turning of the sun.”People in Mesopotamia, Persia, Babylon, and even ancient Greece and Rome all held celebrations in late December and early January, rejoicing at the Sun’s impending triumph over darkness.
And so the Shortest Day came and the year died.
And everywhere down the centuries of the snow-white world
Came people singing, dancing,
To drive the dark away.
They lighted candles in the winter trees;
They hung their homes with evergreen;
They burned beseeching fires all night long
To keep the year alive.
Ever since the Summer Solstice the nights have become longer and the Sun has been riding lower in the sky. By the time of the Winter Solstice the life-giving Sun has reached its lowest point in its transit across the sky. It appears as if the Sun might one day forget to peek its head "above ground". Might the Sun be "buried" in the “under world” perpetually? Life without the sun is not a pleasant contemplation, so humanity has created many stories, activities and winter activities centered on helping to keep the Sun "above ground" for the benefit of the future of humanity.
Thus is the winter solstice is marked as a day of rebirth or a celebration of the life-giving light ceasing its apparent journey to the underground to begin its long march back to ascend to its highest point in the heavens. It is a celebration of the foreshadowing of warmer weather in the future the the return of life-giving greenery and grains to the world by which life is sustained.
Regardless of the reason, the winter solstice has many teachable moments. One can teach on astronomy, the tilt of the sun, the alignment of the rising and setting of the Sun in determining time keeping. One may teach on the theme of death, rebirth and even resurrection and ascension. The days surrounding the winter solstice offer a lot for exploration.
Let's look at how some civilizations around the world observed this time, a time of commonality for all of humanity. Anciently the Romans, Anglo-Saxons, the Norse, the Persians, MANY other cultures, as well as the Christian culture observed the time of Winter Solstice. By whatever calendar you use, the transition from one year into the next is a traditional time to take stock of one's life -- to say goodbye to all that has passed and prepare for a new life ahead; or in the words of a recent presidential candidate "to look forward to what can be, unburdened by what has been."
It is a time of transition as the summer king is metaphorically slain as the sun seems to depart the above-world to spend more time in the underworld. The natural world goes dark. Rituals, dances, pageants, and spiritual vigils are enacted in lands around the world to appease the gods to allow for the sun's return and keep the great wheel of the seasons rolling.
In India Diwali is one of the most widely celebrated festivals. The holiday celebrates the victory of light over darkness, good over evil and knowledge over ignorance. It’s a beautiful opportunity to get together with friends and family and rejoice in the light of one another’s company, while preparing for a fruitful year ahead. also a time to feel thankful for the past year and look ahead to the next.
Regardless of the faith, however, during this time the harvest is safely gathered in and the time of the spirits of Samhain have passed; the nights are longer and in previous centuries throughout the countryside families and neighbors gathered around the hearthfire. Among a number of the different Native American nations across the continent winter is also considered the appropriate time for certain modes of storytelling, a time when long myth cycles are told, learned and passed through the generations.
Often the stories involve monsters. Cultural traditions from around the Northern Hemisphere have long told fireside stories about mythical monsters who steal the sun, play tricks on or try to eat hapless humans in the darkness, encouraging us to "stick to the light" rather than be "lost in the darkness."
In Finnish mythology, it’s told that Louhi, the “witch goddess of the North,” kidnapped the Sun and Moon and held them captive inside a mountain, causing the darkness of winter.
In other mythologies it is monsters from the underworld who seek to capture the Sun to bring it to the underworld. During the Winter Solstice it appears as if they might be successful.
In Greek Mythology, the Kallikantzaros were angry, hairy, gnome-like creatures who lived underground and tried to cut down the tree of life. Like the Kogukhpak, they could also be killed only by sunlight and emerged during the solstice to wreak havoc on homes and villages.
They were reputed to be rather dumb and unable to count past 3, so villagers put out colanders to ward them off. The Kallikantzaros would end up trying to count the holes in the colanders until 
sunrise and then have to go back underground before they could cause any mischief.
But some solstice stories are about kinder beings who help us through the leanest time of year. A variety of deities were worshipped, like Tonantzin in Mexico, Cailleach Bheru in Scotland, Horus in Egypt and Spider Grandmother by the Hopi.
The Scandinavian Goddess, Beiwe, is associated with health and fertility. It was believed that she travelled through the night sky in a structure made of reindeer bones with her daughter, Beiwe-Neia, to bring back the greenery on 
which the reindeer fed.
In Italian folklore, La Befana is a goddess who rides around the world on her broom during the solstice, leaving candies and gifts to well-behaved children. Placing a rag doll in her likeness by the front door or window entices her into the home.
The Feast of Juul was a Pagan Scandinavian winter festival when Juul logs were burned and fires were lit to symbolize the heat and life-giving properties of the returning sun. The Festival of Chaomos was a Pakistani celebration in which a small number of Kalasha or Kalash Kafir people observed the ritual of baths as a part of a purification process. There was also singing and chanting, dancing, bonfires, festive eating and a torchlight 
procession.
The Dongzhi Festival is a very important one for the Chinese and other East Asians. The Dongzhi Festival occurs on or around December 22 when the sun is at its weakest and the daylight is the shortest. Origins of this festival go back to the Yin and Yang philosophy of balance and harmony in the cosmos. With the hours of daylight increasing, there is an increase in positive energy flowing in. Traditionally this festival is a time for family gatherings.
Saturnalia is an ancient Roman Pagan festival honoring Saturn, the god of agriculture and time. During this week of celebration, all work and business came to a halt. Schools and courts of law were closed, the army rested and no criminals were executed. Romans spent Saturnalia gambling, singing, playing music, feasting, socializing and giving gifts to one another. It was a time of role reversal where Roman masters feasted with slaves who were given the freedom to do and say what they liked. During this time homes were decorated with boughs of laurel and evergreen trees, lamps were kept burning to ward off the spirits of the darkness, and temples were decorated with evergreens symbolizing life’s continuity.
