The December solstice occurs during December 20, 21, 22 or 23. It is called Winter Solstice in the Northern Hemisphere, where it is the shortest day of the year. In the Southern Hemisphere, it is the Summer Solstice occurs during June 20, 21, 22 or 23 and it is the longest day of the year.
The Sun’s position
The Sun is directly overhead of the Tropic of Capricorn in the Southern Hemisphere during the December Solstice.
The December Solstice occurs when the Sun reaches its most southerly declination of -23.5 degrees. In other words, when the North Pole is tilted furthest – 23.5 degrees – away from the Sun.