He (Harmony) is a harmonious interactive relationship between Earthly Branches, including the Six Harmonies and the Three Harmonies. The Six Harmonies are: Zi and Chou, Yin and Hai, Mao and Xu, Chen and You, Si and Shen, Wu and Wei. Harmony signifies cooperation, reconciliation, and union; when harmony occurs, harmony prevails. However, harmony is further divided into 'binding harmony' and 'transforming harmony', requiring case-specific analysis.
Examine whether any of the Six Harmonies exist among the Earthly Branches in the Four Pillars of the八字 (BaZi). Zi-Chou harmonize into Earth, Yin-Hai harmonize into Wood, Mao-Xu harmonize into Fire, Chen-You harmonize into Metal, Si-Shen harmonize into Water, Wu-Wei harmonize into Earth. Any pair forming such a harmony constitutes 'He'. It is necessary to assess whether the conditions for elemental transformation (Hua) are fulfilled.
In a BaZi chart, if the Month Branch is Chen and the Day Branch is You, the Chen-You Harmony into Metal manifests, suggesting cooperative opportunities during middle age and prosperous financial fortune.