Shortest Day of the Year Officially Begins Winter

The shortest day of the year in the Northern Hemisphere officially marks the beginning of winter; in the Southern Hemisphere, the beginning of summer.

The December solstice occurs when the North Pole is tilted exactly 23.5 degrees away from the sun.  Timeanddate.com provides a detailed illustration.

This happens at 12:30 a.m. Eastern Standard Time on Thursday, Dec. 22, 2011.

According to the Old Farmer's Almanac, "The word solstice comes from the Latin words "sun" and "to stop, due to the fact that the Sun seems to stop in the sky."

Although the December Solstice officially begins winter, much to the dismay of many in the Northern Hemisphere, it also begins the waxing of increased daylight, culminating in the first day of summer on June 20, 2012.