Winter solstice: celebrating the shortest day of the year

December 21, 2011

First day of winter has deep historical and cultural importance

December 21 is the shortest day of the year, in terms of daylight hours, in the Northern Hemisphere.

At 12:30 a.m. ET (or 5:30 a.m. GMT) on December 22, the hemisphere begins its tilt back toward the sun, marking the winter solstice in this part of the world and slowly leading to longer days.

The solstice is the result of a tilt in the Earth's orbit around the sun that affects the number of daylight hours. The Northern Hemisphere leans farthest away from the sun at this time of year, making the solstice — derived from the Latin words sol (sun) and sistere (stand still) — the shortest day of the year and the first official day of winter. Read more