Some handed-down documents once proposed that ＂Foreign affairs should be handled on vigorous days and internal affairs on soft days.＂ Foreign affairs refer to such suburban affairs as field hunting and warfare, while internal affairs are urban affairs like crowning ceremonies, marriages, funerals, sacrifices, etc. The vigorous days are Chia, Bing, Wu, Geng, and Ren, and the soft days are Yi, Ding, Ji, Xin, and Gui. Bronze inscriptions in the Yin and Zhou Periods are seen in sacrifices, decrees, rewards, dowry speeches, military warfare, field hunting, self-made utensils, etc., which feature many inscriptions about Heavenly Stems and Earthly Branches. According to the published data, sacrifices for deceased elder male and female figures were often held on Heavenly Stem days, and vigorous days and soft days regarding the contents of bronze inscriptions of rewards, sacrifices, and field hunting were not used. As for military affairs and warfare in the Western and Eastern Zhou Period, the Heavenly Stems and Earthly Branches often represented vigorous days and occasionally soft days. Vigorous days and soft days were used simultaneously for other contents. Furthermore, the days of Ding and He often appeared when cast bells and bo were involved.