Four Clashes
Auspicious days unique to each of the four seasons; traditionally forbidden for military expeditions, marriages, and construction.
The Four Clashes refer to an inauspicious day occurring in each of the four seasons, with its specific date tied to the season. Traditionally, it is believed that during these days, the qi field is unstable as the seasons transition, making it easy for certain activities to be impacted or disrupted. Therefore, almanacs often mark these days as inauspicious, primarily advising against undertaking important matters such as military campaigns, marriages, and construction, out of concern that actions taken during these times may encounter setbacks, conflicts, or damage due to fluctuations in the seasonal qi field.