The winter solstice is the shortest day of the year, respectively, in the sense that the length of time elapsed between sunrise and sunset on this day is a minimum for the year. Of course, daylight saving time means that the first Sunday in April has 23 hours and the last Sunday in October has 25 hours, but these human meddlings with the calendar and do not correspond to the actual number of daylight hours.
http://scienceworld.wolfram.com/astronomy/WinterSolstice.html
see http://cantonbecker.com/retrograde for details…
This is the only “Blue Moon” (2nd full moon in December) in 2009. Happy new year!
The date (near March 21 in the northern hemisphere) when night and day are nearly the same length and Sun crosses the celestial equator (i.e., declination 0) moving northward. In the southern hemisphere, the vernal equinox corresponds to the center of the Sun crossing the celestial equator moving southward and occurs on the date of the northern autumnal equinox. The vernal equinox marks the first day of the season of spring.
http://scienceworld.wolfram.com/astronomy/VernalEquinox.html