'Year' in the Bible

In the third year of his rule he gave a feast to all his captains and his servants; and the captains of the army of Persia and Media, the great men and the rulers of the divisions of his kingdom, were present before him;

So Esther was taken in to King Ahasuerus in his house in the tenth month, which is the month Tebeth, in the seventh year of his rule.

In the first month, the month Nisan, in the twelfth year of King Ahasuerus, from day to day and from month to month they went on looking for a sign given by Pur (that is chance) before Haman, till the sign came out for the thirteenth day of the twelfth month, the month Adar.

Ordering them to keep the fourteenth day of the month Adar and the fifteenth day of the same month, every year,

The Jews made a rule and gave an undertaking, causing their seed and all those who were joined to them to do the same, so that it might be in force for ever, that they would keep those two days, as ordered in the letter, at the fixed time every year;