The twenty-four solar terms divide the ecliptic into equal arcs of fifteen degrees, and this one falls at 345 degrees of the sun's apparent longitude. It is a sectional term, a jie, one of the twelve that fall in the odd positions of the twenty-four and open the twelve solar months. The sectional terms and the major terms alternate strictly around the year, so a jie is always followed by a zhong fifteen degrees later.
The system travelled with the Chinese calendar. Japan, Korea and Vietnam all adopted the twenty-four terms and kept their own readings of the same names, and the terms remain in use in each. In 2016 the twenty-four solar terms were inscribed on the UNESCO Representative List of the Intangible Cultural Heritage of Humanity, on the ground that they remain a living framework for agricultural and everyday practice rather than an obsolete scheme.
This term is met under two names, and the reason is a naming taboo. It was originally Qizhe, the opening of the hibernating creatures, and was renamed Jingzhe, their startling awake, to avoid the personal name of Emperor Jing of the Han, whose given name was Qi. The later form is the one in general use today, and both refer to the same point at 345 degrees. The atlas records the older name with the later one noted, since a reader will meet either.