Sì Fèi (Four Waste)
Ganzhi days where the seasonal element is in the 'imprisoned/dead' state; traditionally considered powerless, unsuitable for opening businesses or marriages.
Sì Fèi days refer to Ganzhi combinations where the element of the season is at its weakest, in the 'imprisoned/dead' state. In Five-Phase theory, each season has its dominant element and correspondingly, a weak one. If the element of the day's Ganzhi happens to be the weakest of the season, it is called 'Sì Fèi'. Traditionally, almanacs often consider these days to have insufficient energy, lacking support for endeavors. Therefore, important activities requiring strong momentum, like business openings or marriages, are avoided on such days due to concerns about failure or poor outcomes.