December 21 marks the winter solstice for the Northern Hemisphere in 2017. It's easiest to imagine when you consider an Earth-centric view - instead of having a tilted Earth orbiting the Sun, we imagine that the Sun follows a tilted orbit around the Earth.
Today will offer five hours and 50 minutes less daylight than the summer solstice - the day with the most sunlight. During the winter solstice, the Northern Hemisphere is tilted at its farthest distance from the sun, bringing less light and colder temperatures. For a complete listing of the dates of the winter and summer solstices and the spring and fall equinoxes through 2025, check out this calendar from the U.S. Naval Observatory. Up above the Arctic Circle, the sun never rises on this day.
Exactly How Short Will The Day Be?
The winter solstice happens at 11:28 a.m. ET Thursday.
The winter solstice may be the shortest day of the year, but that doesn't mean you'll have an early sunset.More news: North Korea "directly responsible" for massive cyberattack: WH official
Let's give you the numbers for the day!
Of course, our long winter night pales in comparison with Alaska, where the sun barely climbs above the horizon for three to four hours in much of the Last Frontier. The further north you are, the less sunlight you'll get.
But many are still celebrating the ancient event that has been a tradition in cultures throughout history including Rome and Scandinavia, according to BBC.
The exact times of sunrise and sunset depend on two things: your latitude and geographic location within your time zone.
For thousands of years, people have taken part in rituals to mark the occasion.