"One must require from each one the duty which each one can perform," the king
  went on. "Accepted authority rests first of all on reason. If you ordered your people
  to go and throw themselves into the sea, they would rise up in revolution. I have the
  right to require obedience because my orders are reasonable."

  "Then my sunset?" the little prince reminded him: for he never forgot a question once
  he had asked it.

  "You shall have your sunset. I shall command it. But, according to my science of 
  government, I shall wait until conditions are favorable."

  "When will that be?" inquired the little prince.

  "Hum! Hum!" replied the king; and before saying anything else he consulted a bulky
  almanac. "Hum! Hum! That will be about--about--that will be this evening about twenty
  minutes to eight. And you will see how well I am obeyed!"