Yue Hai (Monthly Harm)
On a day when the Earthly Branch of the day clashes harmfully with the Earthly Branch of the month, traditional taboos advised against praying for blessings, seeking progeny, or taking up a new post.
Yue Hai (Monthly Harm) refers to a day where the Earthly Branch of the day forms a 'harmful clash' (xiang hai) relationship with the Earthly Branch of the month. Traditionally, this disharmony between the branches was believed to bring obstruction and resistance. Therefore, old almanacs often listed such days as requiring caution, with taboos against important activities like praying for blessings, seeking children, or taking up a new official post, as it was thought that external interference could easily cause things to go awry or lead to disputes and gossip.