Leviticus 23:4-8

4These are the feasts of Yhwh, even holy convocations, which ye shall proclaim in their seasons. 5In the fourteenth day of the first month at even is Yhwh's passover. 6And on the fifteenth day of the same month is the feast of unleavened bread unto Yhwh: seven days ye must eat unleavened bread. 7In the first day ye shall have an holy convocation: ye shall do no servile work therein. 8But ye shall offer an offering made by fire unto Yhwh seven days: in the seventh day is an holy convocation: ye shall do no servile work therein.