LAHORE - People across Pakistan and other countries in Asia witnessed shortest day of the year 2013, winter solstice, on Sunday. December 22 was the shortest day with 11 hours and 20 minutes of daylight and 12 hours and 40 minutes of night. Duration of daylight will be increasing gradually after Monday, December 23.
Winter solstice is an astronomical phenomenon which for the Northern Hemisphere occurs in December and for the Southern Hemisphere in June.
For the Northern Hemisphere, the moment of winter solstice is when the sun's elevation with respect to the North Pole is at its most negative value since the previous December. (The elevation with respect to the South Pole is at its greatest since the previous December). The hemisphere has its longest night and shortest day around the moment of solstice with the night within the Arctic being 24 hours long.
Analogous remarks hold for the Southern Hemisphere. Thus, for the Southern Hemisphere, at the moment of its winter solstice in June, the sun is at its greatest height as observed from the North Pole.