Purim is a festival that commemorates the deliverance of the Jewish people living throughout the ancient Persian Empire from a plot by Haman the Agagite to annihilate them, as recorded in the Biblical Book of Esther (Megillat Esther). According to the story, Haman cast lots to determine the day upon which to exterminate the Jews.
The Jewish festival of Purim is probably adopted from the Persian New Year . It is also a holy day for Sufis, Ismailis, Alawites, Alevis, and adherents of the Bahá’í Faith.
Purim is celebrated annually according to the Hebrew calendar on the 14th day of the Hebrew month of Adar (Adar II in leap years), the day following the victory of the Jews over their enemies. Purim begins at sundown on the previous secular day. Theoretically, in cities that were protected by a surrounding wall at the time of Joshua, including Shushan (Susa) and Jerusalem, Purim is celebrated on the 15th of the month; in those cities the 14th is known as Purim dePrazos. Everywhere else, Purim is on the 14th, while the 15th is known as Shushan Purim. In practice, only Jerusalem officially celebrates Purim on the 15th, though a few other cities have observances on both the 14th and 15th because of doubt concerning their wall.
Purim is characterized by public recitation of the Scroll of Esther (keriat ha-megillah), additions to the prayers and the grace after meals (al hannisim,)giving mutual gifts of food and drink (mishloach manot/em>), giving charity to the poor (mattanot la-evyonim), and a celebratory meal (se’udat Purim); other customs include drinking wine, wearing of masks and costumes, and public celebration.