There are four seasons in a year, spring, summer, autumn and winter. The tables have turned and I will come to your house next year.
At the end of a dynasty, the emperor would say, "The days are up." In other words, their family's luck is coming to an end. It's time to change the dynasty.
People often say that 30 years east, 30 years west. Three generations are poor and five generations are rich.
That's the truth.