Yue Xing
When the day's Earthly Branch clashes in a 'punishment' relationship with the month's Earthly Branch, traditionally avoided for lawsuits, taking up office, and marriage.
Yue Xing (月刑) is an inauspicious influence in traditional Chinese date selection. It forms when the Earthly Branch of the day and the Earthly Branch of the month are in a 'punishment' (刑) relationship. Traditionally, activities like litigation, starting a new official post, or marriage on a Yue Xing day were thought to easily cause conflict, legal troubles, or disharmony. The 'punishment' relationship is seen as harmful and confrontational, so almanacs generally mark such days as unsuitable for the aforementioned events. This reflects the ancient emphasis on interpersonal harmony when handling major life events in law, career, and marriage.