Legend has it that the early Druids celebrated the longest and shortest days of the year with a trip to Stonehenge. Now, we get to celebrate the summer and winter solstices in the comfort of our own homes, thanks to Google, which simultaneously posted summer and winter solstice Google Doodles suitable to the appropriate hemisphere.
Dec. 21 is the shortest day of the year above the Earth's equator and the longest Down Under. The days are reversed in June (usually, but not always, June 21).
As Google points out, the winter solstice is technically a single moment "when the sun is directly above the Tropic of Capricorn. This year, that moment will occur at 16:28 Coordinated Universal Time (UTC)." From that point on, periods of daylight get longer.
By the way, that same critter enjoying the winter season also takes refuge from the heat during the longest day of the year -- wherever that may be.
You can see an archive of Google Doodles here.