Why isn’t the Jewish New Year on December 31st? The Hebrews used a lunar calendar long before the Gregorian calendar established the system used around the world. The Jewish calendar contains 12 months and consists of 353 to 355 days.
One tradition of the holiday is the blowing of the shofar, a ram’s horn that doubles as a wind instrument. In biblical times, its uses varied from communicating signals in battle to announcing the beginning of the Sabbath. Now, it is primarily used at synagogue services at this time of year.
At sundown on September 17, Jews will observe Yom Kippur, which means “day of atonement.” During Yom Kippur, observers abstain from eating and drinking and participate in daylong prayers of repentance. Forgiveness is asked for sins committed during the year.