The day of the winter solstice falls on the 21st of December. Today there will be the shortest day and the longest night in the year. And although in many regions winter only has come into its own, the daylight is about to increase gradually then.
The solstice occurs twice a year – in summer and in winter. It is connected with the movement of planets - the sun is located at the greatest angular distance from the equator and, accordingly, the height of its location is minimum for one hemisphere and maximum for another. That leads to the phenomenon as the longest and the shortest daylight hours of the year.
The event got its name due to the location of the sun in the sky - it is being on the same unchanged height during several days at noon, it is «standing», that is why this event got the name of solstice.