This was observed on the tenth day of Tishri. It was really less a feast than a fast as the distinctive character and purpose of the day was to bring the collective sin of the whole year to remembrance so than it might earnestly be dealt with and atoned for. On this day the high priest made confession of all the sins of the community and entered on their behalf into the most holy place with the blood of reconciliation. It was solemn occasion when YAHWEH's people through righteous sorrow and atonement for sin entered into the rest of YAHWEH's mercy and favor so than as the partakers of HIS forgiveness they might rejoice before HIM and carry out HIS commandments.2.
Wayyiqra (Leviticus) 23:26 And YAHWEH spake unto Moses, saying, Also on the tenth day of this seventh month there shall be a day of atonement: it shall be an holy convocation unto you; and ye shall afflict your souls, and offer an offering made by fire unto YAHWEH. 28 And ye shall do no work in that same day: for it is a day of atonement, to make an atonement for you before YAHWEH your Elohim. 29 For whatsoever soul it be that shall not be afflicted in that same day, he shall be cut off from among his people. 30 And whatsoever soul it be that doeth any work in that same day, the same soul will I destroy from among his people. 31 Ye shall do no manner of work: it shall be a statute for ever throughout your generations in all your dwellings. 32 It shall be unto you a sabbath of rest, and ye shall afflict your souls: in the ninth [day] of the month at even, from even unto even, shall ye celebrate your sabbath.
Wayyiqra (Leviticus) 25:9 Then shalt thou cause the trumpet of the jubilee to sound on the tenth day of the seventh month, in the day of atonement shall ye make the trumpet sound throughout all your land.
The Day of Atonement, or Yom Kippur (Yom ha-Kippurim), on the 10th of Tishri, is the holiest day in the Jewish calendar and is entirely devoted to fasting, prayer and meditation. The scripture calls it by a double title, Shabbat Shabaton (i.e., a Sabbath of solemn resting), for on this day solemnity and rest from work are most complete. Yom Kippur celebrates theme of repentance-man's weakness, man's capacity to envision the ideal, YAHWEH's help to the penitent and YAHWEH's forgiveness. According to the Haggadah, the Day of Atonement marks the day when the Israelites received the second Tablets of the Law; they then knew that they were forgiven for the sin of the golden calf. The forgiveness of YAHWEH is conditioned upon man's obtaining the forgiveness of his fellow men; thus the day before Yom Kippur is usually devoted to the mutual asking of forgiveness.
The evening service with which Yom Kippur opens is preceded by the recitation of Kol Nidre, a declaration annulling all vows and oaths of the coming year that are in contradiction to the Jewish faith or that were made under improper conditions (e.g., duress). The practice of annulling vows by confessing them to a court was developed in the mishnaic period. Symbolically, Kol Nidre dramatizes the idea of holding every spoken word as a hallowed pledge. In addition, the words and the melody of Kol Nidre are associated with the suffering and martyrdom of the Spanish marranos (q.v.). Yom Kippur also is distinguished by the number of services held, an additional service, Neila, being chanted just before sunset. In Orthodox and Conservative congregations, the entire day is devoted to prayer and meditation; in Reform temples, two services usually are held, in the morning and in the late afternoon.2.
Agada (Haggadah) (Etymology:Hebrew haggdhh Date:1856)
1 : ancient Jewish lore forming especially the nonlegal part of the Talmud
(Etymology:Late Hebrew talmudh, literally, instruction Date:1532) : the authoritative body of Jewish tradition comprising the Mishnah and Gemara
2 : the prayer book containing the seder ritual ( a Jewish home or community service including a ceremonial dinner held on the first or first and second evenings of the Passover in commemoration of the exodus from Egypt)
Kol Nidre (Etymology:Aramaic kol nidhre all the vows; from the opening phrase of the prayer Date:1881) a formula for the annulment of private vows chanted in the synagogue on the eve of Yom Kippur
Mishnah (Etymology:Hebrew mishnah instruction, oral law Date:1610) the collection of mostly halakic Jewish traditions compiled about A.D. 200 and made the basic part of the Talmud (: the body of Jewish law supplementing the scriptural law and forming especially the legal part of the Talmud; Etymology: Hebrew halakhah, literally, way Date:1856)
marranos (Marrano) (Etymology:Spanish, literally, pig Date:1583 : a Christianized Jew of medieval Spain
ALL FEAST BEGIN AT SUNSET THE DAY BEFORE THE FEAST DATE.
1. Harper's Encyclopedia Of Bible Life cc1946
2. Encyclopedaedia Britannica (Jewish Holidays) 1968