Yom Kippur, the Day of Atonement, is the holiest day in the Jewish calendar, observed on the tenth day of Tishrei (usually September or October) as the culmination of the High Holy Days that begin with Rosh Hashanah. It is marked by a full day of fasting, intensive prayer, and repentance, during which the faithful seek forgiveness for wrongdoing and reconciliation with God and with one another. Tradition holds that on this day one's fate for the coming year is sealed, making it a solemn time of reflection, atonement, and spiritual renewal, often concluded with the sounding of the shofar.