'Thirty' in the Bible

All the chief rulers of the kingdom, the chiefs and the captains, the wise men and the rulers, have made a common decision to put in force a law having the king's authority, and to give a strong order, that whoever makes any request to any god or man but you, O King, for thirty days, is to be put into the lions' hole.

Then they came near before the king and said, O King, have you not put your name to an order that any man who makes a request to any god or man but you, O King, for thirty days, is to be put into the lions' hole? The king made answer and said, The thing is fixed by the law of the Medes and Persians which may not come to an end.

A blessing will be on the man who goes on waiting, and comes to the thousand, three hundred and thirty-five days.