Passover (Hebrew, Yiddish: פֶּסַח, Pesach, Tiberian: IPA: /pɛsaħ/, Israeli: Pesah, Pesakh, Yiddish: Peysekh, Paysokh) is a Jewish and Samaritan holy day and festival commemorating the Hebrews escape from enslavement in Egypt, and is the seven day Feast of the Unleavened Bread (it lasts eight days in the diaspora). Passover begins on the 15th day of the month of Nisan (equivalent to March and April in Gregorian calendar), the first month of the Hebrew calendar's festival year according to the Hebrew Bible. In the story of the Exodus, the Bible tells that God inflicted ten plagues upon the Egyptians before Pharaoh would release his Israelite slaves, with the tenth plague being the killing of firstborn sons. The Hebrews were instructed to mark the doorposts of their homes with the blood of a spring lamb and, upon seeing this, the spirit of the Lord passed over these homes, hence the term "passover". When Pharaoh freed the Hebrews, it is said that they left in such a hurry that they could not wait for bread to rise. In commemoration, for the duration of Passover, no leavened bread is eaten, for which reason it is also called חַג הַמַּצּוֹת ('), "The Festival of the Unleavened Bread". Matza (unleavened bread) is the primary symbol of the holiday. This bread that is flat and unrisen is called Matzo. Together with Shavuot ("Pentecost") and Sukkot ("Tabernacles"), Passover is one of the three pilgrim festivals (Shalosh Regalim) during which the entire Jewish populace historically made a pilgrimage to the Temple in Jerusalem. Samaritans still make this pilgrimage to Mount Gerizim, but only men participate in public worship. (via Wikipedia)