Yom Kippur is the Jewish Day of Atonement, marked by reflection, fasting, and solemn prayers for forgiveness.
The Day of Atonement (or Repentance) is observed on the tenth day of the month of Tishrei in the Hebrew calendar, which usually falls between mid-September and mid-October in the Gregorian calendar.
It marks the end of the ten-day period known as the High Holy Days, (also referred to as Yamim Noraim or Days of Awe) that begin with the Jewish New Year, Rosh Hashanna.
While Yom Kippur is not a public holiday in the United States, many Jewish-run organizations are closed on this day. Learn more here.