What is the solar term of summer solstice?

Summer solstice is an important solar term with many customs. Book of rites? "Eclipse" records that in the Zhou Dynasty, every summer, the emperor personally led courtiers or doctors to the southern suburbs of Beijing to welcome the summer, and held a grand ceremony to worship Yan Emperor Zhu Rong.

The emperor welcomed the long summer to the southern suburbs, which was originally a sacrifice. Because the south is the seat of Zhu Rong and belongs to fire, Zhu Rong itself is Vulcan.