闻鸡起舞：东晋时，祖狄和刘琨二人为好友，常常互相勉励，半夜听到鸡鸣就起床舞剑（见于《晋书·祖狄传》）。后用来比喻志士及时奋发。

rise at cock's crow; diligent and self-disciplined. In the Eastern Jin Dynasty, Zu Ti and Liu Kun were good friends and often encouraged each other, and both rose at cock's crow to play with their swords (see History of Jin·Biography of Zu Ti); (fig.) diligence of man of resolve.