'Fifteenth' in the Bible

On the fifteenth day of this month [is] a religious feast, unleavened bread must be eaten for seven days.

" 'Then on the fifteenth day of the seventh month you will have a holy convocation; {you will not do any regular work}, and you will hold a religious feast for Yahweh for seven days.

They set out from Rameses on the first month, on the fifteenth day of the first month; on the next day after the Passover the {Israelites} went out {boldly} {in the sight} of all the Egyptians