What is the solstice in winter?

The winter solstice usually falls between 65438+February 2 1 or 65438+February 23 on the Gregorian calendar. Because the winter solstice is not fixed on a certain day, it is called "live festival" like Qingming. As early as more than 2,500 years ago in the Spring and Autumn Period, China had observed the sun with earth gauges and determined the winter solstice, which was the earliest of the 24 solar terms, and the time was between 0 and 23 in the solar calendar 65438+February 265438+February, which was the shortest day and the longest night in the northern hemisphere.