Month Breaker (Yuè Pò)
The day when the earthly branch of the day clashes with the month's establishment, making it the most inauspicious day of the month. Traditionally, it is considered suitable only for demolishing old buildings or walls, and not for other activities.
In traditional date selection, Yue Po (月破) is considered an extremely inauspicious day, occurring when the earthly branch of the day clashes with the month's establishment. Historically, almanacs often treated this day as the most unlucky of the month, advising against nearly all activities except for destructive tasks like 'demolishing old buildings or walls' (破屋壞垣). This is because the clash signifies intense conflict and energy dissipation; ancient people believed undertaking new or important matters on such a day would likely lead to failure or damage. Although few strictly adhere to it today, this sha (煞) remains a typical example of 'inauspicious for all activities' (諸事不宜) in folk customs.