'Thirtieth' in the Bible

In the nine and thirtieth year of Azariah king of Judah began Menahem the son of Gadi to reign over Israel, [and reigned] ten years in Samaria.

It happened in the seven and thirtieth year of the captivity of Jehoiachin king of Judah, in the twelfth month, on the seven and twentieth day of the month, that Evilmerodach king of Babylon, in the year that he began to reign, did lift up the head of Jehoiachin king of Judah out of prison;

There was no more war to the five and thirtieth year of the reign of Asa.

In the six and thirtieth year of the reign of Asa, Baasha king of Israel went up against Judah, and built Ramah, that he might not allow anyone to go out or come in to Asa king of Judah.

Moreover from the time that I was appointed to be their governor in the land of Judah, from the twentieth year even to the two and thirtieth year of Artaxerxes the king, [that is], twelve years, I and my brothers have not eaten the bread of the governor.

But in all this [time] I was not at Jerusalem; for in the two and thirtieth year of Artaxerxes king of Babylon I went to the king: and after certain days asked I leave of the king,

It happened in the seven and thirtieth year of the captivity of Jehoiachin king of Judah, in the twelfth month, in the five and twentieth day of the month, that Evilmerodach king of Babylon, in the [first] year of his reign, lifted up the head of Jehoiachin king of Judah, and brought him forth out of prison;

Now it happened in the thirtieth year, in the fourth [month], in the fifth [day] of the month, as I was among the captives by the river Chebar, that the heavens were opened, and I saw visions of God.