Today, however, December 21st, 2009, is longer than yesterday. In fact, this year's winter solstice has more daylight than any other winter solstice in history.
The simple reason is: the Earth's spin is slowing down.
Tidal friction is one of the leading causes.
These distortions cause friction which saps energy from the Earth. When the Moon was formed about 4.5 billion years ago, the day was about six hours long! And this isn't just sunshine day, this is six hours for a full day/night cycle.
It's not a speedy decrease, though. We've picked up only about two milliseconds in the last 190 years. Right now we get about nine hours of sunlight at the winter solstice in mid-latitudes. Next year, it will be a tiny little bit more.
So, if you are one of those who want to find meaning in everything... take solace in the fact that even on the darkest day of the year, it will only get brighter.
*images courtesy of Museum Victoria, and the Department of Physics at the University of Oregon*