Wuxu
From 'xūhào' (emptying/loss); traditionally inauspicious for opening granaries, collecting money, or lending.
Wuxu is a malevolent star (煞) noted in old almanacs, derived from the meaning of 'emptiness and depletion' (虛耗), signifying financial loss or dissipation of wealth. Traditionally, almanacs generally consider days falling under Wuxu to be unlucky, especially prohibiting financial transactions such as opening granaries to collect grain, receiving money, or making loans. The ancients believed that handling finances on such days could easily lead to losses or the emptying of one's household estate, so they deliberately avoided doing so.