But let's not get ahead of ourselves.
The effect at the passage tomb - which predates Stonehenge and pyramids of Egypt - marks the end of winter and the start of new life. Learn more about the solstice and why it's not the coldest day of the year in our scientific guide below. Many pagans, and non-pagans too, will gather today at Stonehenge (the ancient structure is actually thought to have been built to honor the winter and summer solstices) to reflect, release, and celebrate the sun's return. The sun rises at about the same time in both places on Thursday - 7:16 a.m. and 7:17 a.m., respectively - but it sets almost an hour later in St. Augustine - 4:31 p.m. vs. 5:31 p.m. Eastern Time on December 21.
The solstices, and the seasons they mark, are the result of a celestial coincidence. The sunlight causes the mouse to start wearing sunglasses. It's the longest night of the year in the northern hemisphere, and the sun has officially reached its southernmost point as seen from Earth.
In English, the world solstice comes from the Latin word solstitium, meaning "sun standing still".
Thursday is the winter solstice - the shortest day of 2017.
Fáilte Ireland and the Office of Public Works have teamed up for the broadcast on the shortest day of the year.
Harry and Meghan chose their wedding date because of this 'royal rule'
As the Duchess of Cambridge, Kate Middleton, is expecting her third child in April, it's thought that they have planned the wedding for after Kate's due date.
The arctic region sees no sunlight on the day of the winter solstice.
For those of us in the Northern Hemisphere, it's the day with the shortest amount of daylight - less than 12 hours - and our longest night of the year.
For example, today in Birmingham there will be 9 hours, 55 minutes and 48 seconds of daylight.
New York City's winter solstice sunset will occur at 4:49 p.m. The exact date of the earliest sunset depends on your latitude, so it's not the same for everyone.
Do you like darkness?