Yom Kippur is observed on the 10th day of the month of Tishrei and it is a holiday of atonement, repentance and forgiveness. It is observed with a 25-hour period of fasting and intensive prayer. Yom Kippur completes the 10-day period of repentance that starts on Rosh Hashana.
Services on Yom Kippur start with the prayer Kol Nidre that is chanted in synagogues before the beginning of the evening service. Dating back to the Medieval Ages, it has been charged with emotional undertones, thus creating a dramatic introduction to Yom Kippur. The prayer shawl talit is worn during the evening prayer and this is the only evening service throughout the year during which it is worn. Yom Kippur ends with Neila, the concluding service, and the blowing of the shofar marks the completion of the fast.