'Year' in the Bible

The words of Nehemiah the son of Hacaliah. Now it came to pass in the month Chislev, in the twentieth year, as I was in Shushan the palace,

And it came to pass in the month Nisan, in the twentieth year of Artaxerxes the king, when wine was before him, that I took up the wine, and gave it unto the king. Now I had not been beforetime'sad in his presence.

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

and if the peoples of the land bring wares or any grain on the sabbath day to sell, that we would not buy of them on the sabbath, or on a holy day; and that we would forego the seventh year, and the exaction of every debt.

And we cast lots, the priests, the Levites, and the people, for the wood-offering, to bring it into the house of our God, according to our fathers houses, at times appointed, year by year, to burn upon the altar of Jehovah our God, as it is written in the law;

and to bring the first-fruits of our ground, and the first-fruits of all fruit of all manner of trees, year by year, unto the house of Jehovah;

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