The Winter Solstice happens today at 6:22 pm CST (00:22 UTC).
I also forgot to mention, because it happened while my office DSL was down (cutting off my Web servers from the world), that this past Friday had the earliest sunset of the year in the Northern Hemisphere.
Ordinarilly at a juncture like this I would write a dissertation on why the earliest sunset precedes the latest sunrise by four weeks, or why neither coincides with the solstice, but I'll spare you for now. No, the sun is setting later now, but the sun is also rising later, until January 4th, sorry to say.
If you live in the Northern Hemisphere, today is the first day since March 17th with less day than night. Yes, Friday was the autumnal equinox, when the earth's axis was perpendicular to its orbital plane. But because the atmosphere refracts the sun's light about 0.85°, days are always just a little longer than nights on equinoxes.
You can get sunrise and sunset information for your location at Weather Now.