'Fifteenth' in the Bible

And on the fifteenth day of this month [is] Yahweh's Feast of Unleavened Bread; [for] seven days you shall eat unleavened bread.

"Speak to the {Israelites}, saying, 'On the fifteenth day of the seventh month, this [shall be] the Feast of Booths [for] seven days for Yahweh.

" 'Surely on the fifteenth day of the seventh month, at your gathering the land's produce, you shall hold Yahweh's festival for seven days; on the first day [there shall be] a rest period and on the eighth day a rest period.