The winter solstice occurs at 13.11, local time, on December 21. It marks the beginning of the astronomic winter, Info-Prim Neo reports. Between December 21 and June 21, the length of the day increases continuously, while of the night decreases correspondingly. Solstice is the time of the year at which the sun reaches its highest or lowest point in the sky at midday, marked by the longest and shortest days. Today is the shortest day of the year and the night is thus the longest.