'Fifteenth' in the Bible

On the fifteenth day of that month is the Festival of Unleavened Bread to the LORD. For seven days you are to eat unleavened bread.

"Tell the Israelis that starting the fifteenth day of this seventh month is the week-long Festival of Tents to the LORD.

"On the fifteenth day of the seventh month, when you've harvested the produce of the land, you are to observe the festival of the LORD for seven days. The first day is to be a Sabbath rest, and the eighth day also is to be a Sabbath rest.