Passover

Passover, also called Pesach (/ˈpɛsɑːx, ˈpeɪ-/;[2] Hebrew: פֶּסַח Pesaḥ), is a major Jewish holiday that occurs on the 15th day of the Hebrew month of Nisan, the first month of Aviv, or spring.
The word Pesach or Passover can also refer to the Korban Pesach – the paschal lamb that was offered when the Temple in Jerusalem stood, to the Pesach seder, the ritual meal on passover night where it is remembered, or to the Feast of Unleavened Bread which continues for seven days until 21 Nisan (or eight, in the diaspora).
Passover commemorates when God “passed over” the houses of the Israelites during the last of the ten plagues, as recounted in the book of Exodus, and brought them out from Mizraim, from the house of bondage, with a strong hand and an outstretched arm.
This story is recounted at the passover meal in the form of the Haggadah, in fulfillment of the command And thou shalt tell (Higgadata) thy son in that day, saying: It is because of that which the LORD did for me when I came forth out of Egypt. (Exodus 13:8)
The wave offering of barley was offered at Jerusalem on the second day of the festival. The counting of the sheaves is still practiced, for seven weeks until the Feast of Weeks on the 50th day, the Pentecost.
Nowadays, in addition to the biblical prohibition of owning leavened foods for the duration of the holiday, the Passover seder is one of the most widely observed rituals in Judaism.
One of the biblically ordained Three Pilgrimage Festivals, Passover is traditionally celebrated in the Land of Israel for seven days and for eight days among many Jews in the Diaspora, based on the concept of yom tov sheni shel galuyot.