Winter Solstice

The winter solstice, also known as midwinter, is an astronomical phenomenon marking the day with the shortest period of daylight and the longest night of the year. It occurs when one of the Earth’s poles has its maximum tilt away from the Sun. It happens twice yearly, once in each hemisphere. Wikipedia
Date: December 21, 2018
Celebrations: Festivals, spending time with loved ones, feasting, singing, dancing, fires
Significance: Astronomically marks the beginning of shortening nights and lengthening days
Also called: Midwinter, Yule, the Longest Night, Jól
Observed by: Various cultures