The word solstice comes from the Latin "sol" (sun) and "sistere" (to stand still). The winter solstice signifies the longest night and shortest day of the year and marks the official start of winter.
This year, the winter solstice occurs on Dec. 21, and marks the 24-hour period when the North Pole is tilted farthest away from the sun. In the Southern Hemisphere, the summer solstice is happening.
New York City will receive nine hours of light. Parts of Alaska will get only five. In the Arctic Circle, there will be no sunlight at all.
To many countries and cultures around the world, it is a very big deal, but for very different reasons. Since the Stone Age, cultures have worshiped the winter solstice, beginning in about 10,200 BCE. Monuments such as Newgrange in Ireland and Maeshowe in Scotland, tomb structures built from rock and stones, were erected around this time and captured the sun's rays on the year's shortest day.
Stonehenge is another sacred site believed to be inspired by the winter solstice. On that day, the sun is visible through the center of the stone circle if one stands facing away from the entrance. Every year, hundreds of Druids and others flock to the site to partake in ceremonies celebrating the rising sun, seen as a sign of renewal and rebirth.
Pagans come from all over to celebrate the winter solstice. Getty
In Roman times, there were several festivities around the solstice. Saturnalia, a holiday to honor Saturn, the god of agriculture, occupied the week before the winter solstice. It was a hedonistic celebration punctuated by drink, debauchery and gorging on food. Slaves got to behave impertinently with their masters and peasants ran the city in a total reversal of social orders. Schools and shops closed.
On Dec. 25, the elite celebrated the birthday of Mithra, an ancient Persian god of light. For some Romans, the god's birthday was the most sacred day of the year.
In Scandinavia, the traditional festival of lights honors St. Lucia, an early Christian martyr from the days around 1,000 AD, when many Norse people converted to Christianity. On St. Lucia Day, girls wear white dresses with sashes of red and wreathes of candles in their hair to symbolize the candles Lucia wore on her head to illuminate the way as she delivered forbidden food to imprisoned Christians.
The celebration of St. Lucia in Stockholm on the winter solstice. Getty
The Chinese winter solstice celebration is named Dong Zhi (meaning "Winter Arrives"). It celebrates an increase in positive energy caused by the return of longer days. In modern times, it marks a time for families to gather and celebrate the passing year and make new wishes for the coming year.
Crowds in China await the winter solstice. Getty
Native Americans have long observed the winter solstice. For the Zuni, a Pueblo tribe in western New Mexico, the day signifies the beginning of the new year and is commemorated by several days of fasting, praying and witnessing the the rising and setting sun. On the day of solstice, dancing and rejoicing break out as the year is reborn.
The Hopi similarly celebrate, with an all-night ceremony beginning with the setting of the solstice sun, that includes bonfires, dancing and the giving of gifts.
No matter your beliefs, or your place on the Northern Hemisphere, the winter solstice occurs at exactly the same time for everyone. It corresponds to the moment the North Pole is aimed farthest from the sun on the 23.5-degree tilt of the Earth's axis. It is also the moment the sun shines directly over the Tropic of Capricorn.
This year, that time is 11:19 p.m. EST. For those on UTC, Coordinated Universal Time, which is often the same as Greenwich Mean Time, the time is 4:19 a.m. Dec. 22.