'Fifteenth' in the Bible

and on the fifteenth day of this month is the feast of unleavened things to Jehovah; seven days unleavened things ye do eat;

Speak unto the sons of Israel, saying, In the fifteenth day of this seventh month is a feast of booths seven days to Jehovah;

Only -- in the fifteenth day of the seventh month, in your gathering the increase of the land, ye do keep the feast of Jehovah seven days; on the first day is a sabbath, and on the eighth day a sabbath;