When did the days begin to get longer?

Solstice of winter. From winter to the future, the direct sunlight position gradually moves northward, and the daytime in the northern hemisphere gradually becomes longer. The winter solstice, commonly known as the winter festival, the length to the sun, and the division of the year, is an important solar term in the 24 solar terms of the lunar calendar. On the day of winter solstice, the longitude of the sun is 270 degrees, and the sun is almost directly on the tropic of Capricorn. The northern hemisphere has the shortest day and the longest night, and it has begun to enter several cold days.