Is the winter solstice based on the lunar calendar or the solar calendar?

The winter solstice is calculated according to the solar calendar, which is a very important solar term and a traditional festival of the China lunar calendar. Up to now, there are still many places where the winter solstice festival is held, and the time is between February 22 and 23 of the Gregorian calendar every year. This day is the shortest day and the longest night in the northern hemisphere all year round; In most parts of northern China, it is also the custom to eat jiaozi and jiaozi on this day. Astronomy regards winter solstice as the beginning of winter, and the temperature will drop sharply around winter solstice.