Yom Kippur is celebrated/observed on sundown of Tuesday, Oct. 8, and ends at sundown on Wednesday, Oct. 9. The 10th day of the month of Tishri in the Jewish calendar, day of Atonement, the Jewish holiday is spent in prayer and fasting among many people of the Jewish faith. The seven-day festival of Sukkot commemorating the wandering in the desert for 40 years.