'Three year' in the Bible

So He said to him, “Bring Me a three year old heifer, and a three year old female goat, and a three year old ram, and a turtledove, and a young pigeon.”

And when ye come to the land and have planted all manner of trees whereof men eat, ye shall hold them uncircumcised as concerning their fruit: even three year shall they be uncircumcised unto you and shall not be eaten of,

There was famine in the days of David for three consecutive years; and David sought the presence (face) of the Lord [asking the reason]. The Lord replied, “It is because of Saul and his bloody house, because he put the Gibeonites to death.”

After this, the king of Assyria invaded the entire land, approached Samaria, and began a three year siege.