Atonement, Day of: the great annual day of humiliation and expiation for the sins
of the nation, "the fast" (Acts 27:9), and the only one
commanded in the law of Moses. The mode of its observance is
described in Lev. 16:3-10; 23:26-32; and Num. 29:7-11.
It was kept on the tenth day of the month Tisri, i.e., five
days before the feast of Tabernacles, and lasted from sunset to
sunset. (See AZAZEL T0000374.)