Happy Solstice and Happy Yule!
Today, December 21, is the shortest day of the year. The nights of December 20-21 and December 21-22 are the longest of the year. The solstice today occurs exactly at 12:11 PM Eastern U.S. Time.
Solstice is often mistakenly believed to be the start of winter, usually because season winter begins about now in the northern hemisphere. But, in fact, Solstice represents mid-winter.
Solstice is used to celebrate the return of the sun, which begins to strengthen its appearance from here on out in the north. Subsequently, Solstice is celebrated with bonfires -- representative of the sun.