'Year' in the Bible

The words of Nehemiah the son of Hacaliah.Now it happened in the month Chislev, in the twentieth year, while I was in Susa the capitol,

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

Moreover, from the day that I was appointed to be their governor in the land of Judah, from the twentieth year to the thirty-second year of King Artaxerxes, for twelve years, neither I nor my kinsmen have eaten the governor’s food allowance.

As for the peoples of the land who bring wares or any grain on the sabbath day to sell, we will not buy from them on the sabbath or a holy day; and we will forego the crops the seventh year and the exaction of every debt.

But during all this time I was not in Jerusalem, for in the thirty-second year of Artaxerxes king of Babylon I had gone to the king. After some time, however, I asked leave from the king,