Why is the vernal equinox called Tian She?

This problem may be caused by an input error. The vernal equinox is a solar term, and Tian She is an activity, but some people call it Tian She because they are social activities that worship ancestors or gods. Many people think that Chunji in ancient times was a field house, but with the gradual emergence of different forms of sacrifice, Chunji and field house were distinguished.